[danabramov]

>There is seemingly nothing in the AT protocol that prevents sites from defederating and enabling vendor lock-in, just like how every other social media site has switched to requiring you to log in to see links.

Note there is no "federation" in the Mastodon sense; sites don't "talk to" each other. They just all aggregate data from the web. Yes, an app doing that could potentially stop "posting to" and "aggregating from" the web in the future and move the source of truth to a local database. But by doing that, it mostly just loses interoperability--and someone else could start a new app with the already existing data on the network, effectively forking their product with its users/data.

>It's like P2P if it was invented by people who know nothing about P2P

Ironically quite a few people on the team come from the P2P world, which is also why they have experience with where P2P doesn't work. Give https://atproto.com/articles/atproto-for-distsys-engineers a read.