This roster isn't ready to compete, so what's the point? Playing musical chairs with coaches isn't going to transform our team into a contender.
I'm not sure honestly.
This roster is better then people give it credit for.
* We have three all-star calibre players (Tatum, Brown and Kemba) - at least one of those guys is on the borderline of true superstar status.
* We have three role players who are exceptionally good at their role in Fournier (scoring), Thompson (rebounding) and Smart (defence)
* We have two solid prospects who have shown a great deal of promise (Rob Williams and Payton Pritchard)
It's actually a pretty good roster on paper. The roster is either good enough to contend, or else it's pretty [dang] close to it. And many of the players on that roster are far from reaching their prime, meaning the roster (in its current form) can only get better.
Now granted, we didn't have Fournier or Parker most the year, and our top 3 guys (Brown, Tatum and Kemba) have all missed significant games to injury or Covid. It does need to be acknowledged that this plays a significant part.
Rob Williams also didn't really start to emerge until later in the year, and he also missed quite a few games. Normally I'd say all of this offers a good explanation for a team struggling...but in this case I don't. The reason I don't is because of WHO they struggled against. This team lost to a LOT of really bad teams, in many cases it was by way of blowouts. I don't believe those opponents had more talent on the floor then the Celtics with their depleted rosters, so I find it difficult to blame talent or health.
If they beat the bad treams and lost to good teams, different story. When you get blown out by 20+ by a bottom 5 team that's NOT a talent problem. That seemed ot happen far to often for Boston this year .
And this is the problem with the team, unrealistic fan expectations not rooted in reality. Boston has a good team and Boston had a good season. Boston does not have a great or elite team and shouldn't be expected to have a great or elite season. Boston, quite simply, is no where near contender status because the roster is no where near good enough to be near contender status. Until the fanbase really comes to that conclusion, you are left with posts like this and threads like this, that have no semblance of reality.
Takes that constantly downplay our talent that just contended for the NBA title a season ago are the truly unrealistic ones 
Boston didn't contend for a NBA title a season ago.
Boston doesn't even have a top 10 player on the roster, let alone a top 5 one. Until that happens, threads like these will continue to pop and will continue to be ridiculous. Talent wins in the NBA and Boston just lacks talent and all the health in the world, a new coach, or countless other changes made aren't going to magically make Boston a contender until the team just adds more top end talent.
As I've been saying for years, Tatum has the potential to be that guy, but he isn't yet. He has it in him (play-in game, game 3, etc.), but he isn't quite there yet and can't maintain that level of play night in and night out (which really does set apart the true top 5 guys). Until Tatum reaches that level, the team will never be a contender and frankly, if the team isn't careful it might waste Tatum as a top 5 player and end up more like the Bucks the last few seasons (before adding Holiday), then winning a title.