Recently due to various events (namely a lot of people getting off of X-Twitter), Bluesky has become a lot more popular, and excitement for its underlying protocol, ATProto, is growing. Since I worked on ActivityPub which connects together Mastodon, Sharkey, Peertube, GotoSocial, etc, etc, etc in the present-day fediverse, I often get asked whether or not I have opinions about ATProto vs ActivityPub, and the answer is that I do have opinions, but I am usually head-down focused on building what I hope to be the next generation of decentralized (social) networking tech, and so I keep to myself about such things except in private channels.
[...] I mostly believed that anything I had to say on the subject would not be received productively, and so I figured it was best to reserve comment to myself and those close to me. But recently I have received some direct encouragement from a core Bluesky developer that they have found my writings insightful and useful and would be happy to see me write on the subject. So here are my thoughts.
[...] Bluesky and ATProto are not meaningfully decentralized, and are not federated either. However, this is not to say that Bluesky is not achieving something useful; while Bluesky is not building what is presently a decentralized Twitter, it is building an excellent replacement for Twitter, and Bluesky's main deliverable goal is something else instead: a Twitter replacement, with the possibility of "credible exit".
By “Fediverse” people usually refer to “ActivityPub”-based social networks such as Mastodon and Lemmy.
People also rightfully argue that Bluesky, despite the best of intentions, is not decentralised. See How decentralized is Bluesky really? (long read).