I've participated in a lot of incarnations of forums and boards over the decades. They've all changed.
Forums like gamedev used to be far more than the topical discussions. They were community hubs. While they used to include many topical discussions, the site also had a tremendous volume of social and casual conversations. We also had an extremely active IRC channel. Originally the site allowed anonymous posts, and it wasn't until 2005 that they were finally enforced (and I needed to create an account to continue posting).
In the early days, I'd say that topical discussion was about 40% of the forums, and maybe 5% of the IRC chat with the bulk being idle banter. This was true on all the forums I was on, they primarily were for “off-topic” social connections and used the “on-topic” discussions as a draw.
That changed about a decade ago, with big shifts due to social media and enormous Q&A sites.
Sites like StackOverflow (and family) and Reddit currently take most of the topics and discussion. Memes and casual banter have moved to social media platforms. The general conversation has moved to Discord. Every one of them has more focused topics, although Discord still has an awful lot of general banter.