Well, I find it to be a very useful tool. Yes, I get exes and all that on FB and I think it’s kinda cool to have good friendships that have grown of years of distance and growth.
But I find so much more of value there than hookups with 40 somethings. 
Cool thing about social media is we get to choose what we see and the people we have in our lives on it.
My eyes have been opened to a lot of stuff just by being on whether they are true or false even from those 40 something friends.
I have found great value in the side, topic specific groups. I am a part of some philosophical groups as an example.
The stuff I post on my timeline itself is mostly kinda like stream of consciousness about some things I’m passionate about. The real work is in the groups.
Just my 2 cents.