I really fucking hate this about academia.
Nope, you mean "American undergraduate university teaching", not academia.
This is not an academic thing. This is something very peculiar to undergraduate teaching in the US.
I think partly it is the obsession with setting millions of questions for students to do. That way one can make it easy on the lecturer by declaring that the student just do a bunch from a textbook.
The system I went through doesn't even remotely work in that way. At the very beginning the lecturer in question (which eventually included me, at least for a while) made a list of recommended books. There were usually about 4 or 5 of unspecified edition, and there would be a bunch of some of them in the various libraries. Students were very much NOT expected to buy any of them unless they really wanted to. As the courses got more specialised, the list of textbooks would get longer (as no book covered everything), then disappeared completely when it became too cutting edge.
Some of the lecturers more advanced in years would occasionally give a glowing recommendation to a book that went out of print some time during the paleocene. I suspect it was a book they found useful as an undergrad and never checked to see if was still in print.
We then lectured. Every so often, a sheet of about 10-15 questions was handed out such that there were about 4 sheets in a 16 lecture course. The questions and lecture notes are generally handed to the next person when the course moves on to a new lecturer for them to use or ignore as they see fit.
It works well. The question sheet means that a specfic edition of a book or even a specific book at all is not required. Us writing the questions means that there's more incentive to have a small number of good questions rather than vast heaps of busy work.