This is a complete misunderstanding of the AT protocol is and how BlueSky works. The idea is that you can take your entire identity, posting history, etc etc, and bring it with you to a new platform - while still communicating and interacting with everyone that you used to. A better way to think about it is that rather than using a locked in platform like AOL instant messenger (Twitter or Threads), this is an open protocol like email.
The whole idea is that platforms don't have to host people, and that they aren't locked out of the conversation if they're off a platform. But in setting things up like this, Bluesky is incentivized to build a product that will keep users coming back to their platform, rather than a competitor or self-hosting. If you don't like BlueSky's moderation or algorithm, then you can simply roll your own and use that.
Ed Zitron's "Better Offline" had a great episode that got a bit more into that ethos and idea.