A related question is "Should you sign up for Facebook today?". Five years ago I killed my Facebook account (and LinkedIn and G+) and it hasn't bothered me, but... am I missing out on something?
Unfortunately it sucks me into political fake news and lots of other bad things. Blocking all games helped greatly.
On balance the real purpose of Facebook: keeping up with distance family and friends; is a very useful part of life. Thus it is worth it.
The only productive use of Facebook is to keep in touch with people. If you do this using alternative methods (Whatsapp, email or direct phone calls) then you save yourself from the continuous stream of garbage that is the news feed.
I occasionally get pushback from some relatives who tell me I'm not taking part in family stuff. That probably matters to some people, depending on their family dynamics. I simply point out that I also publish stuff online in places they don't choose to look.
I also miss out on some community chatter and the occasional event with a couple of orgs I'm involved with. I don't personally care.
In general, my calculation is that my life is noticeably better without it. I'm not someone who needs constant human contact, in fact, too much is bad for me. I'm also apparently pretty far off-median on the Bell-curve in terms of the value I place on my privacy. YMMV.
Something like http://spokt.com