I wish I remembered where I read this, but a while back I heard a hypothesis about a similar idea to this article: basically that humans only have a certain amount of high cognition tasks in them in a given day, no matter how much time we have. Basically, those low effort rote tasks that take up a lot of the day are less taxing than more complex tasks.

The idea was that even if AI reduces these kinds of tasks, that doesn't actually mean we can fit more complex tasks in their place without burning out.

This research seems to support that idea.