[valdiorn]

Good. There no reason to rewrite undergrad calculus books every semester besides money grabbing. The math hasn't changed in 100 years and there shouldn't be an incentive to write an updated version of the book for the 50th time.

[2devnull]

The language changes, but more importantly students backgrounds and facility with the English language changes. Not that dumbing down the text or replacing old timey words should cost much, but cost disease and all that.

[skeaker]

Granted, but they definitely do not change enough to warrant a new edition every year. This can and has been experimentally confirmed by countless students even before Library Genesis simply by showing up to class with an old edition of the textbook and still learning the material fine.