Not sure what you mean. Sure you can buy any domain and put it behind. But ultimately you are much easier to doxx. Between whois, server IP etc. Then there is the issue of the security on that server too, but that's another story. What would be better is to have a way to put this behind TOR/I2p, that would make things a bit better.
On a centralized website the issue is less present as only the admins of the server can see the details about you, ip etc (maybe mods can too on reddit, not sure), here everyone can see everything, it's a lot more invasive imho. Everytime you upvote/downvote something, your account handle is saved on the post as upvoter/downvoter. This is very juicy data to build profiles and analytics on people.
MagicalVagina
The main issue I see with that is the privacy issue. You can host your kbin instance with your own domain yes, but then everyone can see your domain after your username. And it becomes quite easy to doxx you then...
Between this and the requirement for email address at registration I find the lack of privacy on kbin/fediverse a bit curious. I don't see why such a feature brings value, but at the same time I guess it's more for a technical reason. The list of users who upvoted need to be saved anyway and as it's decentralized anyway anyone can read it. Just wished it was hashed instead, or replaced by some digital signature.
My understanding is no. You would need account migration. And at the moment kbin or lemmy does not support it?
Only Mastodon seem to support that.
https://joinfediverse.wiki/Moving_instances
For me this is still a big issue to solve. But hopefully will happen at some point.
Isn't this violating the GDPR? At least for European citizens.