Libraries still buy their books. And the fact that there are limited, physical copies means that access to the book is still controlled in a way that free onlin

Libraries still buy their books. And the fact that there are limited, physical copies means that access to the book is still controlled in a way that free online copies are not. There is no permanent ownership. A single person can use each copy at a time. That's a vastly different circumstance than the book simply being freely available to everyone everywhere, permanently.