Looking ahead though, Brad is gonna have to really hit on a draft pick or maybe trade a few future ones for another cheap rotational guy. Horford is nearly 40 years old, Jrue is gonna be 35 and Porzingis is also injury prone. Plus all the luxury tax ramifications.
I know there was some personal stuff with Filipowski that probably swayed some teams away (the situation of his "grooming") but he's been decent for Utah and has looked really good the last few weeks. Some 20-point games. He's a 7 foot big who can shoot. This team could have used that as a future building block instead of Scheierman IMO
From my perspective, though, these are largely the problems that any team has when they're a title-contending team - building a dynasty is legitimately impossible to plot under the latest CBA, simply because drafting is as much luck as it is anything else - and for the Celtics-specific issues: we've been talking about how moving on from Horford is going to be a problem for the C's for at least the last three seasons.
The KP trade got us over the hump and nabbed us a title, but I think it's very possible that we don't see another Celtics chip for this core. Getting a second ring, let alone repeating, appears to be harder and harder every year.