I miss the 2000s forums. They were a great source of information that was easy to read, search and for search engines to index. As the posts where often by enthusiasts they were a treasure trove, especially the automotive forums for repair information. The closest we have now is Reddit but doesn’t feel the same and the UX certainly isn’t as good even comparing to 2000s hobbyists installing vanilla Vbulletin and tweaking colours and a few plugins.
A lot of the forums I visited that died, died because success made hosting to expensive as the only option was vertical scaling the database and hard to moneytorise, then things like private Facebook groups took away the various cliques.
I often wondered if I could create a horizontal scalable forum to make hosting costs trivial. Topics are a natural partition key and old posts are heavily cacheable with only recent posts needing lower cache ttls. I think the deployment complexity would be too much for hobbyist though.