I completely forgot that #Reddit was #FOSS! And in fact I think that old code, or a fork of it, is still used to host forums to this day.

Imagine if somebody forked it to support #ActivityPub…

Granted IMHO all #Fediverse forum platforms are going about this all wrong; instead of modelling their platforms after #Reddit, servers should be structured as communities in their own right. i.e. instead of a #Lemmy instance with communities for #Politics, #Gaming, Tech, #Sports etc., there should be a #politics instance, a #sports instance, etc. That might be hard to implement though.