Well then, you're agreeing to basically not seriously contending for a championship for that same period of time. When I say "seriously" I mean top 4 team in the league who can match-up with CLE, GSW, SAS. That crew just isn't at that level of the aforementioned teams and has match-up flaws come playoffs.
This rebuild has been ongoing now for 5 years. Another 3 years is a long time to wait...especially given the amount of assets (and redundancy) Ainge has stockpiled on this team.
Well, sure.
But "contending" in the sense of being on the same level as the teams you mentioned just might not be in the cards.
Even if they trade a bunch of assets for Jimmy Butler, that might not be enough.
So, if it's not clear that this team can get to that level, what's the harm in sticking with this current entertaining and competitive core?
In 4-5 years when the younger guys are hitting their prime, we can see if those guys are good enough to contend.