Imaging if people returned all the defective junk they got from Temu or Amazon. If the price is low enough people aren't returning anything, it's simply not worth the hassle and they'll accept that they got swindled.

For books I'm not sure, assuming that the author actually have a story to tell, but is just lacking the skills to write a book, I don't know that I think you can justify calling it a grift when they're trying to write that book using AI. 370 books however.... Is she really that imaginative?

Some people really are that imaginative, and this author has been putting out successful works for many years before she started using AI.

Nah, stuff like this all goes on Kindle Unlimited where readers pay a sub and authors get paid by the page.

If it's cheap enough people likely won't bother to return them, but if it's rubbish then there will inevitably be reviews that'll lead to people avoiding the author like the plague. That's the real signal of whether or not something is good.