>>64150386
Military, [insert technical field] fiction requires a degree of research most authors would never bother with.
Same reason why most authors of it have backgrounds in or at least adjacent in what they're writing about.

Same reason why while I'm writing my Lovecraft meets Glowies meets Japanese High School I can write about combat, mil antics, weapons and the broad strokes of school life easy, but I gotta spend half a day reading up on the specifics of the Japanese school system, streaming culture, ballet, methane hydrates, etc etc etc.