I agree, I think Circles was great. Between family and actual friends, most people have probably less than 100 contacts to manage. The rest could be lumped into

I agree, I think Circles was great. Between family and actual friends, most people have probably less than 100 contacts to manage. The rest could be lumped into Followers. Even for those, over time, machine learning models could suggest circles to put them in, or even assign them automatically with a manual override if you didn't like the placement. But the basic idea of Circles is sound, and the biggest thing wrong with Facebook (from a user perspective, anyway), is that it doesn't provide something comparable.