I ran the kind of mid-sized forum that catered to an active community of posters and a casual community that showed up for topic-related content (i.e. from sear

I ran the kind of mid-sized forum that catered to an active community of posters and a casual community that showed up for topic-related content (i.e. from search engines). But because most of what we were sharing was either links to news elsewhere, or shitposts, there was no reason to keep using the forum once Twitter went mainstream. I think this was probably the case for many similar communities. If you are utterly massive, your forum is probably still alive.