>>725714369
>I guess it has to do with the culture
General culture. Keep in mind, that up until maybe 100 years ago, it was the norm for you to be considered a full-fledged adult at 15. What do you think sweet 16 meant? What do you think Quinceañera or bar mitzvahs are? Why do you think all those African and Native tribes have their "rite of passage" ceremonies at 13-15? All of these were celebrating children becoming adults in different cultures.
What happened that made everything in the west age up is an insistence on the School->College->Corpo->30s climb into marriage. Because of that for such a long time, western cultures now have an idea in their heads that a 30 year-old looking person is the person right for marriage once they have all their "shit together" and are ready to settle down. That's also why the overton window on what's become acceptable to find attractive has also shifted so dramatically in the west so that anyone with even 18 year-old looks is "child-like" even though in every culture for thousands of years, they would have been an adult for at least 3.