[coffeefirst]

Because it's not actually about "optimizing time," it's about a feeling. A lot of people find themselves in a pattern where they binge-watch a show they don't really even like to fill time. Likewise with social media, at some point you're not sure why you're even doing it. Likewise for people who cut back on video games.

It's the behavior, not the medium, that gives this uneasy feeling all of your time is going to a thing that you didn't mean to spend it on.

On the other hand, if you find yourself sucked into a book for a weekend, odds are it's because you can't put it down and will regret nothing. Nobody binge-reads bad books.