Ainge's most egregious crime is not that he didn't land one of the top five talents over the last few years.
It is that after watching Jayson Tatum play in the ECF's as a 19 year old rookie, and to a lesser extent watching Jaylen Brown play on those same ECFs, he failed to realize and prioritize the single and only thing that mattered from there.
That single thing he needed to accomplish is to find the third, age appropriate, player to pair with Tatum and Brown. Since those 2107 ECF's it has widely been argued that Ainge had the single largest war chest in the NBA for the last 3-4 years and STILL no young 3rd chip. That player could have been an wing, a Power forward or a Center. Flat out criminal...
The concept is to get the young three chips together roughly in the same age range - and let them grow from there. The other pieces around them are interchangeable. The fact that you also possessed the single largest war chest in the league and couldn't get that done is mind boggling.
It's still possible obviously but he's made it much harder on himself than need be.
It's also why, if you think a guy like John Collins is that guy, you might consider a package built around Smart for him. Or a package of Nesmith, Langford, Grant Williams and three first round picks for Collins, etc. I'm not saying Collins is "the" guy (he could be) but some sort of trade like that. Because once you have Tatum, Brown and that third chip that is the fit together - you're in legitimate contention for the next 10-12 years providing reasonably good health.
Time Lord
Collins
Tatum
Brown
Smart
Move someone in besides Collins as you like/prefer as far as the third chip player but that's the goal.
Ainge has had 3-4 years and the largest war chest in the league and hasn't been able to get that done? Brutal...
Heck, moving Hayward for Capella wouldn't have been bad. Once you knew Irving was a total nut job, or at a minimum it was clear Boston wasn't where he wanted to be, trade him for Joe Harris (Brooklyn would have jumped all over that and you probably also get one of Dinwiddie, LeVert or Allen too, anything, something....
Capella
Tatum
Brown
Harris
Kemba better....
I have zero faith that anything meaningful will happen before the trade deadline and Ainge will have royally wasted yet another year of Tatum's and Brown's young prime. Solid work.