Ah, interesting. To be clear, I also meant for specific communities: like for specific hobbies or tabletop games, or niche interests.

They've all abandoned forums and, regrettably, moved on to Facebook or Discord. I'll never understand why they choose Discord, a closed chat platform, for forum type discussions. At this point I feel like Quixote tilting at the wind mills.

I don't understand that either. Discord feels like a hamster wheel connected to a turbocharger.

I am not so sure they all went FB/Discord, some I use(d) for example:

https://www.watchuseek.com/

https://www.rolexforums.com/

https://www.audioasylum.com/

https://www.audioheritage.org/vbulletin/

https://el34world.com/Forum/index.php (A simple machines forum, this guy has been here forever, and he wrote his entire online shop himself)

https://www.civicx.com

There are a LOT of niche forums out there that are not FB/Discord, and keeping track of them is a pain. I do wish newsgroups were still a thing for hobbies.

The trick is finding these, especially with today's crippled search engines. But indeed, it tends to be subject-specific forums rather than general-interest.