No social network is 'worth' anything, especially if you want to get it just because 'everybody else has one'. You will just create an account, try it out for a few hours, and then abandon it. Keeping up with old friends, wanting to share (something) with a group of people, now these are at least some reasons to try it.
I don't think any of the social networks are going to 'die' (Myspace, and even Friendster is still around). Nothing is really 'better' than the others as everyone will have their own reasons to like/dislike them.
Having said that, I like Google+ at least 10 times better than Facebook. I actually post things on G+. Never on public and always directed to one or more circles. On Facebook I ended up just collecting old friends and checking maybe once a week for like two minutes (or the random times when I had to reply to a message). Facebook is cluttered, inefficient, and full of spams and games I don't care about.