I guess that's fair, as a way to make users identifiable with the same user name all over the internet, no matter which platform they are on.
When people sign in using bluesky on https://frontpage.fyi/, they are still bluesky accounts? Or does the account somehow transform into something that exists between both sites?
Is there any real innovation here beyond a combination of "sign in with x service" and having your domain appear as your user name?