You can run your own relay, though:
https://whtwnd.com/bnewbold.net/entries/Notes on Running a Full-Network atproto Relay (July 2024)
I do prefer Activitypub overall, and it’s certainly more mature, but any efforts towards decentralization should be encouraged/celebrated.
You can run your own relay, in that sense the “body” of bluesky is when considered in the abstract potentially decentralized… but when you consider the “brain” of bluesky nodes and the layer of moderation and post/commenting is still locked into a centralized system it is a bit like arguing borg drones have free will because they are physically individual beings.
Or it is like arguing an ant isn’t existentially dependent upon the structure of the ant colony to survive since each ant posesses an individual body with its own six legs.