Here's the thing, I don't think there is anything to do about it, exactly. I attribute the root cause to the network effect. It isn't that fedi is unfit for the use cases I suggest from a technical level, it's that people are already on these other platforms and, to them, the culture of ban-dodging is preferable to a culture of abandoning these services.
I'm not trying to convince you to solve the problem, I'm trying to convince you that it actually is one, that it's not in my head, that it's not just one limited to my personal hobbies.
Like I said above, I'm not sure what the solution is, or if there is one. I have this theory that the network effect is a big part of it, but important people within a certain sphere draw the users, so if you convince the VIPs to jump ship then the people will follow. Evidence for this theory: Trump and Truth Social, which has more activity on it than one might realize.