ActivityPub and atproto are differently shaped. Pitting them against each other is like asking “why need web when we have email”.
ActivityPub is email-shaped. Servers are inboxes sending messages to each other.
atproto is web-shaped. User repositories host data (like personal sites or git/RSS), while apps aggregate from repositories (like Google Reader).
Different topologies lead to different properties. Eg atproto lets user change hosting with no disruption in app experience. atproto also lets anyone build new apps aggregating over existing data.
ActivityPub doesn’t allow either of those things. It’s literally a bunch of small centralized coupled hosting+app services messaging each other.
ActivityPub is email-shaped. Servers are inboxes sending messages to each other.
atproto is web-shaped. User repositories host data (like personal sites or git/RSS), while apps aggregate from repositories (like Google Reader).
Different topologies lead to different properties. Eg atproto lets user change hosting with no disruption in app experience. atproto also lets anyone build new apps aggregating over existing data.
ActivityPub doesn’t allow either of those things. It’s literally a bunch of small centralized coupled hosting+app services messaging each other.