I wish that were true. It's not.

Libraries cost money. Acquiring, storing, maintaining a book in a room, with climate control and a proper shelter, costs more than storing the same book digitally. Providing access to copies of a physical book, to just a million people spread across the US, is extremely expensive compared to doing the same thing digitally via the Internet. Someone should run an estimate on that, it's such an astounding gap in cost as to be absurd.

There are many good arguments for libraries. That they don't cost money or are somehow free, is not one of them. They're subsidized systems of knowledge, primarily for the benefit of people lacking resources to otherwise access that information inexpensively (along with other various community and peaceful space benefits they usually provide).