There was an economic argument I read, probably by David Friedman, asserting that the ability to resell books may lead to greater profit. A student who knows he can resell a textbook for £20 having bought it for £30 may decide to do so if he believes he will obtain £10 of value over the course of use; meanwhile with no second-hand market it may not be worth the price of buying it new at all. The existence of the second-hand market doesn't mean all students buy their books from there: somebody has to supply the books for the market, eventually they presumably become too worn down to have resale value, etc. So allowing resale can sustain demand at a higher price.

Interesting to learn about the compensation on art sale to artists or book borrowing to authors!

On depriving yourself of a digital asset: the Internet Archive's "controlled digital lending" is an attempt to make a library of digital books, only lending out one copy for each physical book owned, in an attempt to not get sued by the publishers. I recall an attempt to make a business of renting DVDs using a similar tactic, but I don't recall the company, and I think that didn't get off the ground -- they had their lawyers who said it sounded reasonable, but they were still sued for copyright infringement and it was too expensive to continue.