So, you're assuming that in our country everyone wants to work in one of these industries... but what if you don't want to pursue an intellectual career?
More interesting, what if you don't have the education for pursuing such career paths? This is the biggest problem for Americans today. Most Americans have low quality schools that cannot prepare for career paths in Engineering and Science. Most of the Engineering labor in the US comes from abroad, either via American universities of the H1B Visa program. What is left for most US citizens educated in this country?