Counterpoint: This ability to "follow people's lives from a distance without necessarily interacting with them in the world" is the only way I have of renewing old friendships with childhood friends, schoolmates and friends from college.

It is a HUGE social benefit to me, as I've moved far away. I don't need Abe's phone number, Betty's email, and I don't expect even Christmas cards updating me on Charlie's family. But if any of them post on FB that their parent or child or dog just died, graduated, or got married (in a progressive animal-rights nation), I can make an effort to let them know I care.