It also builds on top of ActivityPub which is supposed to allow federation with the greater ActivityPub ecosystem ("fediverse"). I guess this would allow people to like or comment your issue or pull request from Mastodon and those other platforms.
I am not that excited about that last part, but federating pull requests sounds like a killer feature and a necessary step for a chance to topple GitHub. If hosting my own forge means I have to either get patches over email or let people register so they can create their own fork here, it's a non-starter for many.
edit: here is Gitea's issue: https://github.com/go-gitea/gitea/issues/18240