You seem to be conflating copyright with access rights. Two very different things. Regardless of your feelings on either, there is no contradiction in holding different views on them.
Well no, it’s about legally gating the ability to copy so the original author doesn’t have to compete in the same market to sell his own book with every other bloke with a printing press and a copy of the book. Everything else is an addendum.
Don’t confuse the social justification with the actual purpose of copyright law just because it’s written into the US Constitution that way. America didn’t invent copyright law.