Exactly this. I'm not entirely certain AI has anything to do with it but my last book purchases have been entirely used.

Our local independent book shop got together with a couple other dozen and started a used book platform. If I have a book I don't want, I'll let them know, if they have a buyer, I just bring it to them and get a small amount of money. They take a fee for the handling and everyone's happy. A used book is usually max half the price of new and there is a decently wide selection.

A lot of online retailers have also started stocking used books as a cheaper alternative.