I think you hit the nail on the head. I was anxious quitting Facebook, but now that I have it feels so much more meaningful to meet with someone I haven't seen in months and have a nice lunch or dinner with them and catch up.
Catching up feels more important and seems to have more substance that way.
The little snippets people share on FB probably are also less personal, imo. It's stuff they're announcing to everyone instead of sharing with you or a small group.
It just doesn't feel like actually "keeping in touch" to me. Feels more like promoted content (from the people and the actual ads).