I deleted FB 10 years ago this month. I can honestly say that I haven't missed it one bit. I realized after a week or so that there was a reason I quit keeping up with 90% of the "friends" I had on there, and this thread has laid a number of those reasons out. I simply don't care what Jesse from the Class of '96 is up to nowadays, and I expect that he feels the same about me.
As has been mentioned, I think it is a direct contributor to depression and anxiety you see in this country. You see Scott and Katy on a vacation to the beach living it up and you're stuck at work. You don't realize that 10 seconds before the beach sunset pic they just posted they were at each other's throat because Katy thinks Scott drinks too much and didn't see little Johnny almost drown in the undertow.
What I'm trying to say is that you can't compare your day-to-day mundane life with everyone else's highlight reel, and that's most of what FB is. That, or pictures of food which I could not care less about.