I know that many folks here don't like the idea of "build around Jay & Jay" because they see that as aiming for the middle. However, I think that perspective overlooks the fact that if the team maintains cap flexibility, doesn't sign anybody to any crazy contracts, and continues to stockpile assets, there will still be plenty of options for improving the team.
The goal is to win a title. To do that the team needs to have at least one if not multiple top tier guys to build around. You also need those guys, and the supporting cast around them, to fit well so that they can thrive together. On top of that, you need to be able to sustain multiple years of contention, because even historically talented teams fail to win titles given a single season (see 2011 Heat).
We've had Jay+Jay for the past two seasons. They are not good enough to build a contender around. Sure maybe if you wait another 3 years they will get there but the Celtics are a contending team right now.
So the answer is you have to give up one of the Jays plus your treasure stockpile of draft picks and get AD. Resign Kyrie. Talent ultimately wins in the playoffs. You saw what the Bucks did to this team. You see how the Sixers are going deep, you see how the Raptors are contending. Because they have top talent.
This year was kind of wasted because we were trying to re-integrate Hayward but he wasn't healthy. He was taking minutes away from Brown/Tatum but he didn't deserve them.
We're going to have to hope that Hayward can regain his all-star form next season because one of Brown/Tatum have to go. They will not be happy with Hayward here, but guess what we pay the man 30m a year so he's going nowhere unless we can swindle the Wizards into taking him in exchange for Beal.
My guess is that the Pelicans are holding out for Tatum and did not want to cave into the Lakers. That makes the Celtics the #1 suitor for AD this offseason.
A lineup of Kyrie, Brown, Hayward, Davis, Horford can absolutely contend for the title against a Durantless GSW.