That's the exact reason why I love the movie theater: no one has any control at all outside of walking out, so everyone pushes their ADHD to the side and commits to the movie for two hours. Once the movie is over, you might still think it was shitty and a waste of time, but at least you gave it a fair shot.
Try watching a slow movie like Gattaca at home, with a dozen devices and apps competing to take your attention away, and see how many people drift off and watch it from the corner of an eye or don't even finish it at all. Does the movie deserve that? Maybe; if only short-form content or frenetic Avengers-like action can hold people's attention from start to finish, then that's how it is. But I, for one, appreciate immensely when people commit fully to something, the way it was intended to, for better or for worse.
And that's why I love the movie theater.