It will, I can think of a ton of services I've used in the past that one day you just stop logging on. You don't even remember the last day of using them, just one day you stop. Then slowly everyone stops. (E.g., AOL, AIM, Geocities, IRC^, MySpace, and most recently Path & Instagram).

I assume the same will happen in my life for Facebook, Reddit, Twitter, etc. One day I will just stop.

^I use IRC for dev stuff now, but there was a good 5 years where it was no longer a part of my life. I was a gamer who played CS in the early 2000s.