I think I don't recall ever being tasked to answer questions set in a textbook at university. The lecturers set problem sheets themselves based on their lecture

I think I don't recall ever being tasked to answer questions set in a textbook at university. The lecturers set problem sheets themselves based on their lectures. Sure, you can still cheat from other people in the same lectures, but that's a different game to having cheating commercially available. That said, the exams were pass/fail anyway and the questions worked on during the course didn't have any bearing on that. Made cheating on problem sets pretty irrelevant, I guess.