I think the "social" part of social networks just moved to group chats. All my friends share updates of their family events, kids' stuff etc.. over Whatsapp and Telegram. Strangers gather over topics that interest them and want to talk about it seem to have moved to discord, slack etc. The whole "broadcast yourself to the world" part of social networks just moved to Tiktok, Twitter, Instagram etc.. I think.
I look back at my Instagram and my last post was 2 years ago. All of the people that I used to see pop up, the people that would like my photos, and I would like their’s, those people seem to be gone. Friends from college, and high school have all been replaced by short videos of strangers, ads, and influencers.
I think the biggest missing piece for me is keeping up with people I know, but wouldn’t otherwise talk to (by any means listed above). It was nice to see those people pop up sometimes, but I have no way of serendipitously finding them anymore. That’s what social media was to me.