There is a lot of talk about how Bluesky and Mastodon work, and how ActivityPub and AT Protocol work. And a lot of arguments over what is better. Each seems to work in fundamentality different ways.
Is one better than the other? Depends on who you ask. In the end, I think that different platforms will attract different users.
Mastodon / ActivityPub:
"I can block people I don't like based on the server they are on."
"Administrators should moderate their servers so I am not exposed to undesired information."
Bluesky / AT Protocol:
"The administrator of a server should not control what I see."
"I can move my account to another server if I don't like the admin."
Hubzilla / Zot Protocol:
"I can control who can see and reply to my posts."
"I can create communities with a limited membership."
"I can move my account to another server if I don't like the admin."
Of course, each one has more features than that, but I think those are the main attracting points.
And I am not sure there is one right answer. Different people have different preferences.