As the growth of Bluesky showed, most users do not care about decentralization as much as they care about usability. In his talk at ATmosphereConf last month, Paul Frazee explained that this is why his team built ATProto instead of using ActivityPub.
What I’d like to see is someone build an ATProto forum like Lemmy, and for it to be fully federated with Lemmy using Bridgy Fed.
EDIT: I know about frontpage.fyi. It does not have communities/subforums, so I would consider it more of a Hacker News replacement.
I switched from lemmy.ml to lemm.ee because I didn’t want to deal with that