Celtics got the right formula when acquiring players.
You don't need to stock your roster with "stars". They went out and got White, Jrue, a Kristap who lost his potential star label and was given up on. They drafted Pritchard who is a full time starter on just about every other team, signed an undrafted Sam Hauser who is another rotational piece who is not just another body, but actually contributes to what Boston does better than any team in the league, which is shoot the 3. All of that added to their franchise tandem in Tatum & Brown, which they also drafted.
Never underestimate a competent front office. And it's not like they didn't try it with a big name. They acquired Kyrie, but when it didn't work, they didn't keep "swinging for the fences" for big names.