^Fair point. Although a lot of first-person stories are presented as someone's actual written or narrated account.
True. But third-person stories often used to be presented as someone's actual written or narrated account, too-- for example, George Eliot's Adam Bede
is told in the third-person with access to characters' inner thoughts, but the narrator occasionally says things that make it clear he's a real person that "exists" in the narrative. That's a lot less popular now than it was in the nineteenth century, though.