This is something interesting I came across.
A Newbie's Guide to Publishing: E-books in Libraries: They Still Don't Get It
Apparently, it's because of monopoly tactics on the part of what the guest author (a librarian) calls "The Big 6 Publishers". I didn't realize libraries have to pay more than $40 for a book I can get on Kindle for $5.
I had always wondered why I can't get eBooks and audiobooks more easily through libraries.
Traditional publishing is headed for a collapse. They're still hanging onto a model from the Great Depression.