You can just take your data to another instance whenever you don’t agree with the policies of your current one. And all your connections/interactions/data should stay intact.

If it works as well as it seems to in the federation sandbox, you shouldn’t even be able to tell that you’re using a different service, the app just sends requests to a different server, and the web url may be different, and your default feeds are generated somewhere else.

Now, you may say that users won’t care about backing up their data, but that can be solved with some open (or paid) archival services.