You make it seem as if the copyright holder is making more money on a library book, than on one sold in retail, which does not appear to be the case in the US.
The library pays for the books and the copyright holder gets paid. This is no different from buying a book retail, which you can read and share with family and friends after reading, or sell it, where it can be read again and sold again. The book is the product, not a license for one person to access the book.