Whoever buys it first. With a centralised database, this is trivial.

Usernames are the same. Who gets @example.bsky.social ? Whoever registers it first. Problem solved.

If you have a central database why do you need atproto?

To stream dns changes from site owners to dns servers. If you want to change a record, you post the change on atproto. DNS servers everywhere just subscribe to the jetstream. That way anyone can run a fast, local dns server which is kept up to date automatically.

How fast can you post messages to Bluesky?

I'd like to see DNS ownership combined with the time range and an owner-unique key so you can go to the website you intended to visit rather than whoever happens to own the domain at the moment.

Why would they still have the server but not the domain?

Domains cost money to maintain. They can lapse, change, or be sold. Sometimes people make mistakes. So to my way of thinking they're great as a short-term named identifier but not as a long-term stable identifier. Would be nice to have both.