Most of the content in Facebook Groups are walled off, not searchable and left for a long death.
Reddit is the only place which still hangs around reminding me of the forums but the way Reddit org has been operating it’s not long time before they wall off the content too. They already require signing-in to even view content for several subs.
Edit: And dev.to is not bad for developers community either. Stack Overflow even though is better, it’s not really community like a forum.
reddit has a great API and is currently much more open and accessible than the patchwork of forums that the article is lamenting the death of. Lots of those required signup as well, and it became unwieldy to have 5-10 different accounts for those.
I can't really see a financial motivation for reddit to require signups sitewide, as it would ruin their search rankings and seemingly not help them sell ads.
Edit: And dev.to is not bad for developers community either. Stack Overflow even though is better, it’s not really community like a forum.