Facebook is pretty awesome between the ages of like 15-22, and then like from 40+ years old if my relatives are any indication. In my mid-ish 20s it's a whole lot of who gives a fuck on the Facebook tube. Choosing to use or delete Facebook is not anything I would describe as a major lifestyle decision. At this point in my life I'm not missing anything except baby pictures and people publicizing their existential and spiritual problems personally.
Some younger people reading this thread who use it socially might be thinking of deleting their accounts and my advice as a stranger? Hang in there and don't potentially victimize your social life to make a point. People may not go the extra 10 yards to get in touch.
I thought FB was a great social tool at that age (and AIM in middle school, that was really mind-blowing shit at that point in the history of personal computing and the Internet) and I truly hope younger people still get something out of it like I used to.
However, if the amount of time you spend on Facebook is having a negative effect on your lifestyle, and you recognize that it does, and you continue to do it anyway, you have a psychological addiction. If you want quitting Facebook to be a positive change in your life you need to recognize that it is a symptom and not a cause. Deleting Facebook isn't going to fix your broken family or make you muscular or give you 20 more IQ points. Your brain doesn't have a Facebook receptor that is being specifically satisfied by killing time on it.
You're addicted to dopamine rewards from being the gluttonous lethargic piece of shit who we all are deep down. You won't spend 5 hours on Facebook every day but if you're the kind of person that does that you are going to spend those 5 hours doing something equally pointless to satisfy yourself unless you make deliberate and continued constructive lifestyle choices.
I've especially noticed in recent years that I am a slave to that easy pleasure - procrastinating, sex and masturbation, some recreational drugs. I'm not addicted to any of those things. I can go a long time without any of them, but god damn I need a spoonful of some indulgence to not be miserable and that's OK. Pleasure is a good thing. But supplementing cheap pleasures like Facebook and cocaine and excessive masturbation is only treating a lack of pleasure and not constructing long-term habits to consistently reinforce pleasure in a beneficial way.
And for what it's worth I actually have Facebook still. I check it maybe twice a year now in case an old friend is looking for my number of something. No wall posts, no user indexing - it is functionally disabled. I never felt like I needed to quit the thing, it just became useless. So it's there. Just unused.
No one will probably read this, I've typed it for me and that's OK.