TL;DR. If you ask me, the essence of social media today is the algorithm and the "social curation". Is what I see dictated by some behind the scenes algorithm and by the mob (votes, views, engagement, flags, clicks)? It's social media.
But fair enough. Don't forums have subforums for different interests, topics and specific discussions and sub-communities? They have the option to follow other members or topics in a customized consumption experience. In my personal experience on large and small forums, including those I administered or moderated, most users lived their entire life in specific subforums. The user that only posted in the CPU subforum, or the Nikon subforum. The user who created the "photos of flowers" or "case modding" topic and only hung around there with kindred souls in their micro-community. Forums were really reddit at a smaller scale.
> I guess all you'd need to change is a modification for making threads bump on vote behaviour instead of latest-post.
This is downplaying the weight the hidden algorithm has on what you see on HN. Much like every other social media site and very much unlike classic forums, submissions and comments here live and die at the hand of an algorithm that decides whether today you get to read about the Israel/Gaza conflict, about Democrats/Republicans. This algorithm is driven on one hand by the social aspect (people deciding what's media and what isn't, hence the "social"), on the other hand by some obscure engagement rules that none of us can see or define.
I don't make it "seem" more complicated, it "is" more complicated because experts don't fully agree on exactly what social media is. Everyone tries to use their experience, preference, and common sense and these all vary.
P.S. The current top comment isn’t there because it’s the most recent, the only objectively correct one, or a mod pinned it. It’s there because the algorithm driven by social engagement decided it’s the media I should see first.