You’re not forced to be on Facebook but if you’re not then you’re the one person people will always need to do extra work to invite. And that’s for friends, without Facebook you won’t even hear about public events until after they have happened.
Don’t get me wrong, we always invite the two guys without Facebook, but I know both of them feel a little shitty about having to be extra trouble.
Eventually people will leave, and someone have to take the first step, but that’s a really shitty step. The reason I say eventually, is because nobody uses Facebook for anything but events, I haven’t used messenger since they forced you to use the app and I’m not the only one and when I look at my news feed none of my close friends (or myself) have posted anything since New Years.
So Facebook have become a satellite network we check for events, and that’s one step from being obsolete.
This is anecdotal of course, but it is true for both my and my wife’s friend circles.