@Zergling_man @antichrist_hater it's not just that, it's also that ActivityPub had major improvements over OStatus that OStatus was just impossible to extend for, like post scopes, from what I've heard (I wanted to read OStatus docs but they're all gone, but considering what I've seen of the design, I believe it)

Pleroma was designed as an ActivityPub-centered software first, OStatus second; and it was originally designed as a GNU Social frontend, mind you, so it's not "largely driven by Mastodon". In both cases, they kept compatibility for OStatus, because communicating with the people was still the most important. I don't believe either would've taken off if not for that.