How Young Go-Getters Add Value to Humanity

Tyler Cowen posits an intriguing theory on why so many hot young college graduates enter law, consulting, or finance:
You will seek out jobs which reward a high “G factor,” or high general intelligence.  That means finance, law, and consulting.  You are productive fairly quickly, you make good contacts with other smart people, and you can demonstrate that you are smart, for future employment prospects.
This somewhat mundane -- and much commented upon -- trend, however, may very well have some much deeper, much more significant antecedents, as Cowen claims:
The age structure of achievement is being ratcheted upward, due to specialization and the growth of knowledge.  Mathematicians used to prove theorems at age 20, now it happens at age 30, because there is so much to learn along the way.  If you are a smart 22-year-old, just out of Harvard, you probably cannot walk into a widget factory and quickly design a better machine.  (Note that in “immature” economic sectors, such as social networks circa 2006, young people can and do make immediate significant contributions and indeed they dominated the sector.)  Yet you and your parents expect you to earn a high income — now — and to affiliate with other smart, highly educated people, maybe even marry one of them.  It won’t work to move to Dayton and spend four years studying widget machines.
Cowen's deeper presupposition, that humanity's accumulating mountain of knowledge and technology has transformed how productive inquiry can even happen, is something that isn't discussed nearly as often as it needs to be -- especially outside of the academy.
If society is increasingly too complex for even the brightest among us, might we need to reconsider, well, everything?