IMO Facebook is just 9gag now, plus a huge dose of fake news, it's a shitty forum-type of site like digg or reddit but with terrible UI (here are the top 50 comments, you want the rest, keep clicking "More..."). Nobody shares anything personal anymore, it's just weblinks and, as I said, 9gag-ish content, plus people raging on topics like politics. I think the youth are now sharing their lives through the Snapchat-features of WhatsApp and Instagram, but lucky for Facebook they also own these 2.
If Google (as rumoured) redesigned their homepage to give you a personalized "news feed", that will eat Facebook's lunch. They need some social features to keep people engaged though.