Hot take: if you want data sovereignty for your social media data and you are using mastodon—or even ActivityPub based services in general—you are on the wrong platform.
The fundamental way that activitypub works is the antithesis of how data sovereignty needs to be designed.
But once you get over that, the way it is implemented by the major platforms today is _also_ the antithesis of how you need to implement these to have good data sovereignty practices.
This doesn't mean that they aren't worth aiming for, but it also means that it isn't as simple as "it's decentralized and therefore better."
@hrefna on a possibly related note: is JSON-LD or RDF actually good for data sovereignty? (My gut feeling after 4 years is "no")
@thisismissem I can argue that it is, at best, neutral in this regard.
Probably a lot worse than neutral in practice, however.