You need to look at #nostr, which solves the problems that you describe for #Mastodon
- accounts and posts are not tied to a URL, but to a public key, so there is no problem with migration between domains (they need to develop a story of key migration, but that is well-known territory)
- migration of user interfaces is easy (I use 5 regularly for their various advantages)
- there is a good payment story with lightning
- it solves the censorship problem, which is much worse on Mastodon than on Twitter. The problem is that Mastodon acts as a slander machine, spreading false rumours in that tags section and censoring people trying to give opposing points of views.
Here is the details on that:
https://primal.net/e/note1dve7jxdmrk5j3euww7p07ere9ju768ywjksdqptpnkrlrchutu9s6v8net
And you can see the story in a number of other web interfaces here:
(But there are also apps for Android and iPhone, desktop etc...)
Is it perfect? No.
But it is bringing something very new to the table.