These AI predictions never, ever seem to factor in how actual humans will determine what AI-generated media is successful in replacing human-ones, or if it will even be successful at all. It is all very theoretical and to me, shows a fundamental flaw in this style of "sit in a room reading papers/books and make supposedly rational conclusions about the future of the world."
A good example is: today, right now, it is a negative thing for your project to be known as AI-generated. The window of time when it was trendy and cool has largely passed. Having an obviously AI-generated header image on your blog post was cool two years ago, but now it is passé and marks you as behind the trends.
And so for the prediction that everything get swept up by an ultra-intelligent AI that subsequently replaces human-made creations, essays, writings, videos, etc., I am doubtful. Just because it will have the ability to do so doesn't mean that it will be done, or that anyone is going to care.
It seems vastly more likely to me that we'll end up with a solid way of verifying humanity – and thus an economy of attention still focused on real people – and a graveyard of AI-generated junk that no one interacts with at all.