True, but they also just don't fucking advertise it at all, and its on a forgotten subdomain only linked to in a blogpost, and the date on the page still says 2023 at the bottom.
Well, its easy to build an app on atproto, but lord forbid you want to do anything with a pds.
The activitypub spec is so much easier to read and understand than the pds spec.
Also, portable identity is possible on activitypub as well, its just not implemented in many projects.
Its still not really decentralised, because all the pds's need to be crawled by a relay, but its still a pretty cool technology.
Someone made flushes.app which I think is a good demonstration of how it can be used.
Check lemmybb.