Usually isekai lets you sidestep the problem (?) of introducing an audience to the fantasy world by having the main character learn what their new world is instead of having grown up there and knowing what it's like already. Which makes it annoying when the main character is reincarnated from the real world into a fantasy as a baby - then the conceit makes no sense.
Though, a couple seasons ago there was one about a princess who died in a fantasy world and came to the real world, went to medical school, died and went back to the fantasy world to save the kingdom with advanced surgical techniques.