There's no monopoly at all in the US. But the US society has tools at its disposal that make high qualification jobs possible (high end tooling, high end education with a high output of graduates per year, etc).

A highe % of the population can work in high qualification jobs, but the society will also always need cleks, bakers, taxi drivers, etc.

The effects that high qualification jobs have, with the higher value added to products and services, permeates all of society with higher wages than in other countries.