alt Hacker NewsAcademic textbooks are mostly a racket, forced upon a captive market (the student body) and - with rare but notable exceptions - not books that most students would care to hold onto after graduation.
Historically, your lazier instructor took problem sets out of these books which put extra pressure on students to buy them. There's also the accelerated edition turnover in the publishing industry, so that teachers always get the latest edition, which has slightly different problem sets than the one from two years ago, even if the material is the same as it was two decades ago. It's hard to feel much pity for any lost sales suffered by those outfits due to online distribution of current texts.
Today, any instructor with access to an LLM can come up with unique problem sets and solutions with relatively little effort for a whole semester's coursework, and just do that every time they teach the course. Yes students will just use LLMs to help them solve the LLM-generated questions - so more in-class quiz sessions are likely to become the norm.
Ok, a publisher stakes their reputation on having reliable problem sets. If you used an LLM, you'd have to proof every single problem to make sure there weren't issues with it that would lead to student's having unintended difficulties with them. Yes it "saves time," until a problem is assigned whose "right answer" takes not only far longer than all the others but is ridiculously complex and impossible to grade or complete in any reasonable amount of time.
Switching the problem sets every couple years is a difficult task in and of itself, and it also keeps answers from circulating amongst students, and saves time for the professor who won't have to do the above every single week, they can just pick however many problems they like out of the book for the relevant section.