They are at least less powerful and resourceful and you can simply switch your instance or make your own.

None of this is true for Twitter.

A Mastodon instance owner can read everything you've ever posted, log everything even if you deleted it, doxx your IP and your private messages, delete or modify everything about your account on a whim and block you even if you make an account elsewhere. Plus they can keep very quiet about it since they have zero accountability.

So yeah, you can go to another instance, but better keep some kind of backup because you could be gone without notice

That's exactly right, to a point that decentralize app like Mastodon would be valid alternatives when everyone run its own instance (and is able to secure it), of course that's in theory already possible, but in practice it's difficult.

So does Twitter without the possibility to host your own instance or move your data to another one.

Isn't that one of the reasons for decentralization? Less power and data for a single instance.

You say this like he's quietly minding his own business and some pesky journalists are revealing what a dickhead he is. That is not the case, he is outspokenly a dickhead. He wants to broadcast what a dickhead he is _so_ badly, that he bought the worlds foremost social network to control the medium.

What Musk says publicly is basically useless. All the truly important information about him has been the result of deep investigations through papers and documents and third party accounts.

So yeah, Musk gets investigated very often so we know things that he would rather keep hidden. Now what about your Mastodon admin with an anime profile picture?