It doesn’t take long for a boxing dream to die. Pryce Taylor’s was over in nine seconds, the amount of time it took for a bow-tied judge in Lake Charles, La., to declare his opponent the winner in an Olympic qualifier in December.

Minutes later he sat in a corner near the locker room, his 6-foot-4 frame deflated. Mr. Taylor was a shell, and his yearslong dream was over: there would be no trip to Tokyo, no parade with family in the stands, no tattoo of the Olympic rings.

That Mr. Taylor would even land in this ring was already a long shot. He had started boxing only four years ago, and the sport had given purpose to his otherwise rudderless adulthood. He was 23, so this shot at the 2020 games — his first — was most likely his last. By the next Olympics, he would be 27, the amateur boxing equivalent of an old-timer.

Thirty years ago, a fighter’s failed Olympic bid would be less of an ending than a nudge toward professional fighting.

But Mr. Taylor is from New York, and boxing in the city is not what it used to be.

All over Brooklyn and Manhattan, expensive boutique boxing gyms with names like Shadowbox and Rumble have popped up, supplanting the city’s bare-bones fight clubs. There are very few cheap places to train anymore, and very few coaches. What’s more, much of the prizefighting scene has abandoned New York City for Las Vegas and the West Coast. It has always been difficult to make a living as a boxer in New York. Now it is nearly impossible.

After the match, as he tenderly unwrapped the tape from his bandaged hands, Mr. Taylor faced a future he had hardly considered. The Olympics were meant to be his springboard toward professional boxing; he had no contingency plan. The day after his loss, he wandered aimlessly in the Louisiana arena as qualifying bouts went on, eating beignets and drinking soda.

He didn’t know if he could keep fighting. He didn’t know where he would live. He didn’t know how he could earn money. He had 72 hours before his flight back to Brooklyn, the beginning of a future he couldn’t envision.

“It’s different when you actually don’t make it,” he said the day after the fight, staring into space.

The decision to become a professional boxer is a turning point for any amateur fighter. To take that avenue effectively seals off any chance of pursuing an Olympic run, and it kicks off a parallel process of training, sponsorship deals and negotiations with promoters.

The timing of such a move is critical. An amateur wants enough of a record that he can prove his experience, but not so much to suggest he is past his prime.

New York City used to be the place for a fighter like Mr. Taylor to make that leap, a path followed by native sons like Sugar Ray Robinson, Jake LaMotta and Mike Tyson.

“At one point in time, there were fights every weekend in almost every borough,” said Bruce Silverglade, who runs Gleason’s Boxing Gym, the iconic Brooklyn fight club. There were plenty of cash prizes to go around, he said, so fighters could spend time during the week training. But Mr. Silverglade — himself a Hall of Famer, vaguely reminiscent of Mick, the grizzled coach in “Rocky” — has watched professional boxing’s slow retreat from New York City, a phenomenon he said was driven by high insurance rates and the steep overhead costs of presenting fights in the city. It has pushed promoters to more performance-friendly markets like Las Vegas.

“Fighters cannot enter the sport of boxing and become a fighter and make a living at it,” he said. “Professional boxing has basically left New York.”

Pryce Taylor seems paradoxically unmoved by boxing’s intensity. He rarely arrives to workouts on time. He goes to sleep somewhere between 2 and 3 a.m. Little seems to animate him — including the fact that he is one of the country’s best amateur fighters.

He stumbled into the ring relatively late in life. He was already 19 when he found Cops and Kids, one of the last remaining free boxing programs in the city. The sport became his lifeboat, adding structure and purpose to a life he admits did not have it otherwise.

Until he found boxing, Mr. Taylor’s ambitions were at best vague. Four years ago, his plan was to play basketball for a community college, transfer to a bigger school like Notre Dame, and then get drafted by the N.B.A. Instead, he dropped out after one year and never went back. Later, he thought about trying to become a rapper. It was not until he stepped in the ring that Mr. Taylor’s ambitions and abilities aligned. Despite losing his first fight, by September 2017, he had decided he was a boxer.

But Mr. Taylor’s diffidence has, at times, stunted him. He was a natural, but he was uninterested in the work required. “I just stopped training because it got boring,” Mr. Taylor said with a shrug. He was so unprepared for the 2019 regional tournament — one of the few events that could qualify him for the Olympic trials — that his coach said Mr. Taylor shouldn’t bother fighting.

Mr. Taylor ignored his coach’s advice and traveled on his own to the regionals in Reno, Nev., anyway. He won on a knockout in the first round, but lost in his second bout.

“I could have beat him if I actually trained,” he said of that opponent. The realization snapped him into a more intense regimen. By that fall, he had qualified for the 2020 Olympic trials in Louisiana. It was a remarkable turnaround for an athlete who had fewer than 30 fights in his official amateur bout book.

His mother, Ayaba Bennett, said she has noted the change in her son. “Very focused, like an arrow,” she said. Her son often lights candles in their home and trains by punching so hard that the air from his fists snuffs out the flame.

Mr. Taylor is an admitted loner outside of the ring. He has a small handful of friends that he texts regularly, but he rarely goes out. He spends most nights in the small one-bedroom he shares with his mother and his younger half brother, watching anime or playing video games.

“People are timid when they’re around me,” Mr. Taylor said one evening at home in Brooklyn. He could be quiet, he acknowledged, and he knew people were intimidated by his silence and his size. He didn’t mind being by himself.

“I like the space,” he said. “I like to watch my shows.”

For much of his boxing career, Mr. Taylor has earned money volunteering as a sparring partner for professional heavyweights. He’s given cash under the table, essentially paid to be pummeled.

As far as sustainable futures go, a boxer’s options are limited. Of the few who can actually maintain professional careers, most don’t continue full-time beyond their 30s. Some dabble in professional fighting and then repurpose their careers into coaching. Others find work as private trainers.

Rarely do any of these paths yield full-time employment — Mr. Taylor’s trainer, Benny Roman, a former Olympic coach, has a day job himself. He trains aspiring fighters at night and on the weekends.

Those who have seen him fight believe Mr. Taylor has a shot at being a successful professional boxer, though almost all acknowledged his biggest obstacle was his own lack of focus. With his height and lean, powerful physique, he is a promoter’s dream, said Aureliano Sosa, a coach for the Cops and Kids program.

“They’re going to be all over him,” Mr. Sosa said one afternoon, watching Mr. Taylor train at Sweatbox, a no-frills gym in Sunset Park founded by an alumnus of the Cops and Kids program.

Mr. Sosa also boxed with Cops and Kids while growing up in Sunset Park and briefly pursued a professional fighting career. He left the sport because he stopped loving it, he said, but years later, he returned as a coach. Over the last decade, he has shepherded several of his athletes into professional fighting.

Mr. Sosa believes it will happen for Mr. Taylor, but he also recognizes the challenges ahead. The months after Olympic trials are a bad time to try and score a promotional deal, Mr. Sosa said, since many promoters have already signed fighters that advanced through the tournament in Louisiana.

“I tell all the fighters that you should not just rely on boxing,” Mr. Sosa said. He has encouraged them to consider careers as announcers, judges or coaches.

“There’s life after boxing,” he said. “That’s what I try to teach them.”

As Mr. Taylor fights with his own future, his sport, too, is at a crossroads. After decades as a blue-collar pastime, boxing has been repurposed for the fitness-obsessed young professional.

Mr. Taylor wandered into that culture gap in November, when Mr. Roman directed him to Bout, a chic boxing gym tucked into a Downtown Manhattan high-rise, for a sparring session. Mr. Taylor, looking at the gym’s Google listing, was confused. Was his coach sure he had the right place? It didn’t look like a fight club, he said. He arrived and wandered uncomfortably between the sleek, mirrored rooms until he found his workout partner. Together, the heavyweights dawdled, waiting their turn in the ring among Bout’s weekend workout crowd.

Within the last decade, a new breed of Instagram-friendly boxing culture has emerged. Celebrities like Adriana Lima and Karlie Kloss post glamorous boxing workouts on social media. Boutique boxing clubs like Bout, Rumble and Shadowbox opened in New York, with high-energy classes, high-tech equipment and a price tag to match: at Rumble, a package of 30 group classes costs $900.

“What kept me afloat are the hipsters who came to train,” said Ray Cuadrado, the president of amateur boxing in New York and owner of Brotherhood Boxing in Bushwick.

Mr. Cuadrado said there has actually been an uptick compared to the number of fight clubs in the city a decade ago. But the renaissance has left some of boxing’s traditions behind. As the sport’s clientele has gotten whiter and more affluent, its core of professional fighters has shrunk, along with the more affordable city clubs that first introduced them to the ring.

The crisis has been particularly acute for Cops and Kids Traditionally, free programs like this had been the gateway for promising fighters from poorer neighborhoods. Mr. Taylor said he could have never started boxing if he had not found Cops and Kids.

But recent years have seen these programs eliminated almost entirely. Cops and Kids, which was created by the Police Athletic League in 1986, has closed almost all of its gyms. The Police Athletic League cut the program from its roster in 2009.

Since then, Pat Russo and Dave Siev, two retired New York City police officers, have fund-raised privately to keep the gym alive.

“Free gyms don’t exist anymore,” Mr. Russo said one afternoon, standing in a cinder block basement in Flatbush that housed the program’s last remaining Brooklyn outpost before a flood wiped the property out. “If it wasn’t for the landlords that give us free spaces, we couldn’t afford it.”

Since the gym was destroyed last summer, facilities across the city have opened their doors for Cops and Kids athletes. The landlord of the flooded property has offered to renovate the space. Mr. Russo expects the new gym to reopen in March, and he hopes all of his athletes return.

“You’re paranoid that the kids who get to these other gyms don’t lose interest and go back on the streets,” he said.

After his failure in Louisiana, Mr. Taylor spent a few weeks in Brooklyn considering his options. He thought about giving up on boxing altogether, but in the end, decided it was time to go pro.

“I’m feeling a lot more motivated now,” he said. He was signing up for the Ringmasters, one of the last high-profile amateur tournaments in the city. If that went well, he would return to the national team qualifiers. He didn’t expect to box in the 2024 Olympics, but a good showing would help launch his fighting career.

His immediate modest goal, he said, was to win the Ringmasters tournament. “Get some recognition.”

Within the year, he could start boxing for money.

It was the most purposeful Mr. Taylor had felt since he first tripped into the sport. In February, he found a job training teenagers at Sweatbox, a gig that came with the added benefit of giving him a free place to train. He shook off some of the technical fighting styles he had first embraced in his amateur training and channeled some of the aggression he had learned to temper. He would continue working with Mr. Roman.

In one of his first sparring sessions since his Louisiana defeat, Mr. Taylor said he felt looser than he had in months. He moved deliberately and with purpose inside the Sweatbox ring. He had ditched his boxing shoes, which he had blamed for some of his tension in Louisiana. Instead, he moved around the ropes in untied Nike trainers.

Dripping with sweat, he marveled at how much more relaxed he felt. It was noon, and he was not scheduled to work for another three hours. He could make it home and relax for a while, get lunch or play video games before returning to Sweatbox. But he looked at the clock and shook his head.

“If I leave now,” he said, swinging at a speed bag, “I wouldn’t come back.”

Ali Watkins is a reporter on the Metro desk, covering crime and law enforcement in New York City. Previously, she covered national security in Washington for The Times, BuzzFeed and McClatchy Newspapers. More about Ali Watkins