And this is why Boston won't win the title any time soon. You just can't do that. You have to pick a direction because otherwise you are just going to keep plodding along like Boston has for the last 5 years i.e. a good team, but not one that is going to realistically win the title.
Man, I don't even know what you're talking about. They have picked a direction -- they're building around Tatum and Brown and trying to win now, while doing what they can to set the team up to maintain an open window during the time those guys are under contract.
It seems to me that you think that if the Celtics don't have a clear cut top 5 MVP candidate, they should be in a permanent state of rebuilding and/or compiling assets.
Do you actually watch the Celtics? I only ask that because it seems to me that your preferred strategy would make the team very difficult to enjoy if you actually watch them. What you're advocating for only makes sense if you're happy to kind of keep the team on the side burner of your attention until they're at the top of the league again, at which time you'll buy in again.
You're entitled to that version of fandom, if that's what you like. I just can't get on board with it.
Even if the idea is "well they should go absolutely all in on the short term," that's not a smart strategy either. No team can be built to definitively win in any given season. Look at the Clippers this year. You do not want to be in a situation where you are all in on one season. That's a precarious place to be as a team or as a fan. The best strategy is to build a team that has the basic ingredients to be very, very good, and then make moves to maintain those ingredients and build a sustainable support system around them.