I beg to differ, most so need to change. You just cherry picked the one example that needs the least change.
I'm sorry, but realistically, most textbooks do not need to change every year at the K-12 level. Algebra, Trig, Calculus, Physics, Chemistry, Earth Science, Biology, Classics for English classes. These are all very well established topics with very little change at the core/basic level taught in K-12. The only classes I can think of that would benefit from being updated is History, but even then, most of the history I learned was pre-1940's and the core of those topics are do not dramatically change from year to year.
The only group that really benefits from the cost savings is College students because they get raped every quarter/semester on books whereas the subjects taught in K-12 are pretty static with used textbooks readily available (from what I remember at least).