School is about wide exposure to concepts that wouldn’t be encountered elsewhere. The goal is to teach students how to think, not what to think. The actual subject matter is irrelevant.

I don’t remember if the area of a triangle in my geometry homework was 5 or 7 and it genuinely doesn’t matter. What I do remember is that formulas are generalized way to solve problems.

Nobody needs to remember the content of fictional literature. But malleable brains do need to examine it critically so they can examine anything critically.

A book report is simply a demonstration that you can ingest and comprehend non-trivial information. That’s it. The content is irrelevant.

A book report on Timothy Zahn’s Star Wars novels serves the same purpose. But your instructors need to be familiar in order to assess your competency so they stick with the classics.

Having completed book reports on any topic at all better prepares you to study history (or any topic) later in life because it is literally just “how to internalize information”.