> So much so that most people are incapable of reading a book,

> Or even watching a 3 hour movie.

I agree with your thesis in general, but I don’t think these two in particular are comparable the way you’re phrasing them.

I have read books in a single five or six hour sitting but those were “by accident” in the sense that I wasn’t expecting to finish the book the day that I started them, I went into them with the expectation there would be pauses. Books work well with this type of interruption and have well-defined chapters.

A three hour movie, on the other hand, I see as a commitment I must try to not interrupt because it is designed as a single experience. Breaking it up detracts from the artist’s goal. Before starting it I must immediately look at clock and do some math: can I even begin to watch this movie, considering that in two hours I should <be preparing dinner | sleeping | picking someone up | something else>?

A similar phenomenon is when we don’t feel like watching a two-hour movie “because it’s too long” but then happily binge watch fours hours of some TV show instead. Even if we ignore TV shows are often designed to be more addictive, the fact that you have clearly delineated stop points—chapters, if you will—makes them a more manageable commitment.