Came here to say this. Basically if you are worried about control in the Mastodon ecosystem (as a general issue, not specific technical flaws or vulnerabilities)... you didn't really understand it. Not an insult, its complicated, and a lot of information right now is a variation on the theme of "pick from these big existing sites/people who run mastodon so you can bail on twitter right now with very little effort"

If your worried about privacy, or control, or anything else like this. Just look at running your own self hosted Mastodon instance... Thats. The. Point. Of. Decentralised.