I'm not sure it matter less in other sports since it doesn't matter all that much in other sports either (except football, I think, but more for the skills required to run such a large organization of both players and coaaches than strategy). Of course what really matters is they simply can't replicate what makes Boston (a stable roster) or Miami (a stable front office and coach) succeed.
Don't forget Hinkie and Brown in there. In the end Hinkie didn't draft or trade very well beyond being lucky Embiid was injured, and Brown had too much faith in Simmons given their history. But ownership just hasn't made it possible for anyone to actually do their jobs really. Or hired the wrong people to do them.
Fun thought exercise (except not fun at all): will both Maxey and Embiid be on the Sixers in 2025? Neither of them? I think they have to try and get Harden to stay and take a couple of more shots. Or they have to trade Maxey to take a couple of more shots. Like you say the peak is going to pass and once Joel is done (hurt, traded, contract up) there's not going to be anything for a few years at least.