That's a rather bastardized and twisted representation of copyright and fair use.

The "whole point" of copyright was to promote the authorship of original creative works by legally protecting the financial income of those authors. The "whole point" of fair use was to make exceptions in cases where it's clear that the usage doesn't result in a market substitute and deprive original authors of their income.

The end-goal of LLMs is to ingest all of that original content and reproduce it with expert-level accuracy, promising to be the know-all, end-all product. If wildly optimistic predictions of LLM proponents turn out to be correct then they will never buy a book again, they will have no reason to. And this is precisely what the copyright was designed to protect authors against.