As others have pointed out, AI's are not needed to produce crappy repetition which is eagerly gobbled by the masses, i.e. Hollywood, Netflix, and werewolves and vampire stories by the penny. And there is a huge audience for those.
What I think is going to happen is that even when I'm searching for information in subject X, I might need to fight through a lot of AI fluff to get anywhere. If that gets too bad, I may loose the incentive to use the Internet altogether, or to use the open internet. If I can't use the open Internet, I'll have to go to the closed one, which by definition is under the control of funded parties.
Today, we have a semblance of "verifiable personhood". Imagine what will happen when we use AI to break that too. For example, an AI could create a fictitious "Derek Mains" who post photos to Instagram, has a Facebook account with photos from his childhood all the way to his retirement, a profile in LinkedIn with a lot of professional connections (AI fictions like him but also many real people that the AI gulled), and even a Github repository from the time he tries to create a cooking recipes website, full of PHP and Python code. Derek Mains is now traveling the world and tasting new types of food, posting regular updates on Twitter/Tumblr/Mastodon, and Wikipedia, where he edits food-related articles. Not very often compared with everything he does online, but once in a while he engages with other people(?) in Twitter where he is partial to party X.
What would real people do when they discover that the Internet is full of "Derek Mains"? How do governments and power factions will use this? Wouldn't be sweet to own the closed Internet when the open one is a wasteland?