I've seen quite a few streamers that click through the text and don't care about the story.

It's even more common among playtesters. Ever noticed how some games seem to go out of their way to avoid any subtlety and repeat the major plot points at least 4 times? Or give way too many hints for the easiest of puzzles? One of the causes is that a game was playtested within an inch of its life.

Someone ended up optimizing for the kind of player who doesn't care much, because the playtesters didn't care much - they were only there for a paycheck.

But I've also seen a couple of streamers that can just scan entire pages into their mind in a second and click through text while retaining all the information.

I thought myself a quick reader, but even I was in a disbelief seeing someone read this quick on the first playthrough.