As for books that haven't fallen apart from being used as intended and merely are no longer desired, my local library generally sells them off at bargain prices.
What happens when the books don't sell?
What happens when the books don't sell?
If all these companies were doing was burning star wars tie-in novels and harry potter sequels nobody would care. That's not their goal because they already have those in their training set. The whole point here is to find rare or underappreciated books from the pre-digital era which nobody ever made publicly available in a digital format.
BTW destroying them isn't even necessary for scanning. It's the easiest way because removing the binding and turning it into a flat stack of papers solves many problems but there are actually dedicated book scanners designed to hold open the book while its photographed, and un-curling pages in post-processing was already a solved problem long before people were using AI to correct images.