>>529670754
>How come every well known 'delphic' contents are all about Older brother x Younger sister?
It's narrative shorthand. Younger women preferring older men and vice-versa are stereotypes because it's extremely common, to the point I would argue that it's probably at least a simple majority of people who believe this. Therefore, in a work where the sibling dynamic is important—specifically romance—a younger sister is the default setting. Otherwise, how would the sister being older influence the narrative? If she's more of the caretaker, then it subtracts from the sibling relationship and skews it towards the motherly, which is not necessarily appealing in this case. If she's the one who wears the pants in the relationship, it becomes less appealing to most men and women who prefer the man to be the one ultimately in control. If the sister being older does not appreciably change the narrative, then the default setting is used because it just "makes sense."
