It's super cool that it supports this, heck I've used it when no other options were there (and thank git I could! It made a nightmare into just a little more work instead).
I will say though, it's most of the other software forge features that people normally talk about adding Activity Pub support for (issues tracking, merge requests, tracking forks, CI tooling, handling documentation, etc).
I would love to see the Mozzilla foundation double down on ActivityPub and host a Forgejo instance or work with Codeberg for hosting.
I wonder how much Github being the primary place for FOSS source code limits people around the world from joining the movement.