The difference here though is that the copyright holder sustains himself by the sales of his particular chosen text, so it doesn't matter that the text can be reproduced infinitely.
Big if. Practically, the movie studios aren’t poor because their product has instances of infringement.
So the median person who is harmed when something competes with his book authorship is someone making 20k p.a., not someone who is a major shareholder of a big firm.