I consider a big part of the problem to be notifications, and their respective default settings.
Before smartphones (generally speaking), the majority of your notifications were on your computer. If you walked away from it, you were no longer getting them.
Today, you've got a notification blaster in your pocket/purse, which is bad enough for work stuff, but if you participate in social media, it's a FOMO machine too. By default, all of your notifications are artificially urgent.
I'm a little older than the average HN'er, so my attitude in life has been closing my social circles to be a very small group of people with richer interactions, as opposed to enlarging it to a large group with less rich interactions. Because of that, it's been pretty easy to wean myself off of FB (not that it was ever a big part of my life in the first place), and I've never considered Twitter, Instagram or anything else to be that interesting. I will admit that I enjoy Reddit - those cute animal gifs are quite relaxing after a stressful day, but I don't use Reddit the way most people use FB or other social media.
When it comes to notifications, I turn a lot of them off. I keep my work notifications on during the hours I consider myself available (for urgent stuff, people know they have to call me), and tightly restrict other notifications that can be distracting.