I mean, every website except one you run on your own hardware has this exact problem: whoever is running it owns it completely, and they set the rules (within legal boundaries).
The only ways you can avoid this are:
Run your websites yourself (which is kinda low-value; imagine the Geocities era, but everyone has to set up the hardware and the networks and the domain names and everything themselves), or…
Stick to websites that have an easy “escape hatch”, where you can easily bail at any time. This is how Lemmy/Mastodon/Kbin and the Fediverse at large are designed: if your local server admin sucks, well, you can just join a different server, and you can still see content from all the other servers as before (assuming the place you “escaped” to hasn’t blocked them).
I mean, every website except one you run on your own hardware has this exact problem: whoever is running it owns it completely, and they set the rules (within legal boundaries).
The only ways you can avoid this are: