I remember some such forums that were really popular and that provided a lot of value for some sub-communities. Nowadays, those needs seem to be mostly filled by Discord servers, Facebook groups and other walled-garden products. HN being a notable exception, but that seems to be running on its own stack.
My question is: is this just a matter of something going out of fashion (perhaps driven by monetization interests), or are there technical/UX/safety reasons why you'd recommend a different solution for a new community project in 2022?
source: I ran & hosted zx6e.net, a niche but active motorcycle forum, for over a decade. Sunsetted the site for lack of user growth combined with becoming sick of operating php trash.