[michaelmrose]

Libraries who purchase books for a much smaller discount than other bulk buys drive more sales than they cost. For a new release which is when most sales are made the library only buys n copies when n * x copies are simultaneously desired by readers who want to read your book now not after a 12 week waiting list. This is to say they drive more sales than they cost.

Here is an interesting answer on the topic.

https://www.quora.com/How-does-a-library-pay-royalties-to-th...

They also provide a net benefit to society by encouraging knowledge and literacy. There is a social expectation that physical goods are sold in most cases without expectation that seller will retain contractual control in order to derive maximum profit. Example nobody liked when Keurig sold coffee pots that wouldn't work with generic or indeed even older official pods via electronic tags in pods.

Also keep in mind that that we all exist in a society there is no reasonable expectation that you have a moral right to be able to use societies apparatus to maximize profit if its at societies expense. Limits are the norm.