E.g., like Assassins Creed Origins’ museum mode where you could learn about Egypt. Less so things like Hearts of Iron or Crusader Kings.
There’s plenty of educational games aimed at elementary school students, but I’m curious if there are any aimed at older audiences, like the game equivalent of a nonfiction book.
There are quite a few of them for learning languages. For example, Learn Japanese RPG: Hiragana Forbidden Speech is a game focused on learning to read hiragana.