I was quite addicted to FB and found I was wasting an awful lot of time on it. In the early days I didn't seem to get a lot of notifications but I think over the past few years, things have changed and I found it really irritating. I agree though that it can be useful when trying to keep in touch with far flung family and friends.
On the other hand I think there can be downsides to being on FB, not least when you have people living out their lives in public and including comments that can spark quite unpleasant outcomes.
I eventually weaned myself off it and now only visit FB 2 or 3 times a month. My nearest and dearest now keep in touch by e mail, text, Skype, Messenger, phone or even, sometimes, a letter!