Books.Google.Com was deemed fair use because it only shows previews, not full downloads. Internet Archive is still under litigation iirc besides having owned a physical copy of every book they ever scanned (and keeping a copy in their warehouses) they let people read the whole thing.

I’m surprised Google hasn’t hit its competitors harder with the fact that they actually got permission to scan books from its partner libraries and Facebook and OpenAI just torrented books2/books3, but I guess they have aligned incentive to benefit from a legal framework that doesn’t look to closely at how you went about collecting source material