Moments after Game 7 of the Eastern Conference finals ended last month, Jayson Tatum and Jaylen Brown embraced each other.

“They said we couldn’t play together,” Tatum said with a wide smile.

That had been the most pressing issue facing the Boston Celtics since Tatum, 24, and Brown, 25, were handed the reins to the team before the 2019-20 season. That year — Tatum’s third and Brown’s fourth in the N.B.A. — they led the team to within two wins of reaching the finals. Since then, they have faced questions about whether Boston could be a championship-caliber team built around them.

Those questions were at their loudest earlier this year — dominating TV panels and podcasts — when the Celtics were 18-21 and on pace to miss the playoffs. Instead, a remarkable turnaround propelled the Celtics into the finals, against Golden State, for the first time since 2010.

“We definitely thought about and had conversations about trading for a number of the great players that were sort of thought to be available over the past 10 years,” Wyc Grousbeck, the owner of the Celtics, said in an interview. “It’d be wrong to say we never engaged in trade talks with player X, Y or Z.”

But, he added, “we valued our guys more than, apparently, the market did.”

The trend in the N.B.A. over the last 15 years — though it didn’t originate then — has been to chase the creation of so-called superteams at the expense of developing continuity and nurturing young players. The 2007-8 Celtics, who brought in Ray Allen and Kevin Garnett to complement Paul Pierce through blockbuster trades and won a championship, were a prominent example of this.

Since then, several teams have emptied their cupboards of draft picks and young players to acquire big-name stars — as the Celtics did — in a leaguewide arms race to compete for mercenary championships. This has coincided with the player empowerment movement, where top players have tried, often successfully, to be traded to teams with other stars.

This has left the players’ new teams on edge, wondering if giving up all the picks and young players will be worth it.

The Celtics tried to get in on the trend — they traded for Kyrie Irving and signed Gordon Hayward to a big free-agent deal just after drafting Tatum in 2017 — but today’s team is the result of yearslong investment in young players. The Celtics are on the doorstep of a championship with a foundation that goes against what has become conventional wisdom about team-building in the N.B.A. Whether as a result of luck or shrewd front office work, or both, the Celtics’ approach is paying off.

In recent years, the All-Stars Jimmy Butler, Kawhi Leonard, Ben Simmons, James Harden, Anthony Davis and Paul George have been among those to engineer trades. Irving forced a trade out of Cleveland to land in Boston.

Almost every time a star was rumored to want out of their situation, the Celtics would be linked to the trade talks. Few teams could offer young players as talented as Boston’s or as many draft picks, some of which Boston acquired in a heist of a deal with the Nets as they created their own superteam in 2013.

Grousbeck declined to comment on what deals Boston came close to making. In at least one case, the star seemingly made the decision for the Celtics. Davis’s father, Anthony Davis Sr., publicly said that he didn’t want his son playing in Boston — a signal that even if Davis were traded to Boston, he wouldn’t re-sign once his contract expired, making it less worthwhile for the Celtics to part with their top players in a deal.

“I think that what happens is you want to trade draft capital if you get the right deals and if you feel like you’re close enough to winning,” Danny Ainge, who was Boston’s president of basketball operations from 2003-21, told Sports Illustrated recently. “None of us know what would have happened in different circumstances.”

In some cases, superteam gambles worked — at least in the short term. The Toronto Raptors won the championship in 2019, led by Leonard; the Lakers won a title in 2020 with Davis. But the Nets won just one playoff series with Harden before he forced a trade to the Philadelphia 76ers in February. To get Harden from Houston, the Nets had given up the 24-year-old center Jarrett Allen, who made his first All-Star team this year with Cleveland.

The Nets’ one series win with Harden came against Boston in the first round of the 2021 playoffs, with Brown out injured. The Celtics, left behind in the superteam arms race, seemed adrift. Some of their recent first-round draft picks, like Romeo Langford (2019) and Aaron Nesmith (2020), looked like misses. Irving and Hayward were gone. Kemba Walker, a former All-Star whom the Celtics had signed to a maximum contract to replace Irving, had been injured and playing poorly. Suddenly, Boston looked like a team that had, unlike the Raptors and Lakers title teams, held on to its young players for too long.

The day after the Celtics were eliminated from last year’s playoffs, Boston simultaneously announced that Ainge was stepping down as team president and that Brad Stevens would replace him. Stevens had been the team’s head coach for eight seasons, but he had no front office experience.

Grousbeck said he pitched Stevens on replacing Ainge, citing Stevens’s tenure with the team and a “personal bond” that he had with ownership. At the news conference announcing the move last June, Stevens said he had discussed the possibility of taking over the position with both Ainge and Grousbeck, and that he told Grousbeck: “I love the Celtics. I want to do what’s best for the Celtics.”

One of Stevens’s first moves was to hire Ime Udoka as coach, Udoka’s first leading role after nine years as an assistant. Grousbeck said he wasn’t worried about the inexperience of Stevens and Udoka in their new jobs.

“I went to Ime and Brad before the season started and specifically said in person, ‘I’m not stressed about how this season starts,’” Grousbeck said.

There are countless examples of professional sports owners preaching patience but not practicing it. As the season progressed, the Celtics mostly kept the faith that they could win with Tatum and Brown as their centerpieces.

“Now, did I start worrying in the first half? Yes, I did. But I kept it to myself,” Grousbeck said.

After their 18-21 start, the Celtics went 33-10 and earned the No. 3 seed in the Eastern Conference playoffs. Most of the players in their finals rotation were drafted by the Celtics and are 25 and younger, including Tatum (24), Brown (25), Robert Williams III (24), Grant Williams (23) and Payton Pritchard (24). Marcus Smart, 28, was drafted by the Celtics in 2014 and named the defensive player of the year this season.

This would appear to leave the Celtics in strong shape for years to come. They’re in the finals and many of their players haven’t hit their primes. But championship windows can be slim. After this year, the N.B.A. will have crowned at least five different teams as champion in seven years. The Celtics might end up regretting not trading for Davis or another big name if they don’t win a title this year. After all, just one year ago, when the Celtics looked to be locked into mediocrity, the Phoenix Suns came within two wins of a championship, only to slink out in the second round of this postseason despite being the West’s No. 1 seed.

But if Boston wins, perhaps the next team will think twice before striking a deal when the next Harden or Simmons tries to force a trade. The Celtics aren’t quite the model of patience — a stroke of luck, it seems, felled their superstar trade negotiations — but what they have appears to be working just fine.

Not that Grousbeck is interested in taking a victory lap.

“I don’t think anybody needs any advice from us about building a team,” Grousbeck said.