Frankly "borrowing an ebook" just does not make sense to me.
After many millennia of humanity striving to preserve knowledge we now have a way to make unlimited perfect copies of books but instead of really making use of it we instead put an unnecessary complicated system in place that makes the book artificially unavailable after some time.
Its like how early cars in Britain had to be preceded by a guy with a flag, really- trying to force and limit a new invention into the existing outdated system.
Or worse it even reminds me of book burning, removing perfectly fine book copies that could make it more likely for the book to survive in the future, like has happened for personal copies of many famous ancient text with the original texts being long lost.
I'm sure every ancient librarian would love to be able to provide books for every human alive - yet we now have the means of doing that, but choose to artificially sabotage it!