It's not that it is "better" but that the choice is individual, not up to the mastodon server. In Mastodon, you trade Elon for some other group of individuals, so what happens if they make decision on moderation or content you do not agree with?

ATProto is designed around accounts that are independent of data host, application, and moderation, all in the name of giving users individual control over these things. It's like if every Mastodon user ran their own server, but without the overhead