None of the ones traditionally considered 'social media', don't see the point and apparently many have become unregulated free-for-alls where many post nonsense/conspiracy theories or argue with others which seems pointless to me. I belong to a few forum sites like this one which are specifically formatted with topics/threads/etc. so you can pick/choose what you want to look at or comment on. FB is mostly formatted by person, so when someone tries to turn it into a discussion/forum site seems rather clumsy and not really setup for that purpose.
Social media like FB changed something in their settings a few years ago so I was suddenly able to see posts from friends-of-friends even if I had NO idea who they were. I don't think that change was well publicized and most probably don't notice the change. Previously, you could only view the posts of those who you were 'friends' with. Rarely used it since then.