This is a somewhat lame suggestion but in the spirit of Pinboard/del.icio.us or Bluesky/Twitter, a well-supported copy of OG Friendster or Facebook could just work to some degree.

I don't use social media outside of old.reddit if that counts but would strongly consider something like this. It would be easy to describe to friends; my friends/family over 30 are nostalgic and those under 30, especially those living on their own now, are curious about alternatives to the current state of things.