It's also much easier for me to keep in touch with relatives in remote places. I get a little of their life every day, but don't have to spend hours on the phone with everyone to do it.
Can I get rid of Facebook? Of course. Facebook didn't even exist for the first three decades of my life. I think people who have a Facebook "problem" really have mild "internet addiction" and Facebook just happens to be their poison.
FWIW, the best part about Facebook is grandma doesn't send me 43 emails a day containing jokes about the weather anymore. :)
Sure I can call them. Sure I can send them email, or paper letters, or text messages. And for specific communications, that's fine. But for just sharing what you're up to from day to day, or week to week, many people appear to prefer using Facebook, and find other methods inconvenient.
Lots of red flags. If you can't get rid of Facebook, Twitter, Google+, that means you are an exhibitionist, or narcissist.
Or, you are selling something. That's why I'm on Facebook and Twitter: to help sell my software and apps.