> I like Facebook to keep up with friends who I don't get to see very often...For example, I literally haven't seen some of my high school friends since we graduated 22 years ago, but I know all about their kids and families and their recent successes at their jobs.

Why is that so useful though? If they were really important to you personally, you'd have kept in (active) touch with them. If you don't live in the same town as them, then you're not likely to encounter these people outside of a reunion.

I'm not trolling or criticizing, I'm genuinely curious why "staying in touch" in this way is so valued. I can see the value of LinkedIn (it's always possible you may develop business or professional relationships with passing acquaintances from your past and I take care to prune my connections occasionally) but the draw of FB is a bit mysterious to me.