Do you have any reason to believe that faster maturation is in any way positively correlated with dominance, success or ‘first world’ status, either for individuals or nations?
WRT individuals Desmond Morris, author of “Third Chimpanzee” and “Guns, Germs & Steel”, believes that exactly the opposite is true. While he admits the evidence is lacking in many key areas it seems at least plausible that earlier maturation leads to increased social problems and decreased physical and mental potential. He points to examples of the Watusi where physical size is quite impressive and yet sexual development starts later than in western societies. Teenage related social problems are low by western standards and remarkably low by the standards of African cultures integrating into a western system.
I really can’t see any reason for believing that having a population of 15 years olds that are physically fully mature but mentally incapable of handling their physical strength and reproductive potential as being a bonus to our society.
We also know that absence of close male contact, something we deem to be a social problem, is at least partially and perhaps largely responsible for the increase in early menarche amongst girls seen in the last 20 years. It’s hard to see how that gives any society a benefit.