There's no real difference in that situation, but people don't generally read paperback books when out to dinner with friends, while driving on the highway, while walking on a crowded sidewalk, during a movie at the theater, during class at school or in a meeting at work... which are all common situations where I regularly see people glued to their phones.

Why do you assume that people are wasting their time when they’re on their phones?

I wasn't necessarily implying that what people are doing on their phones in those various situations is a waste of time, but trying to showcase the sheer distractive power of smartphones vs traditional media.

I have to admit to two of those :)

Four. >.>

But then, when I was in college, I'd read paperbacks while riding a bike to class.