The reason why America doesn't have more good jobs is that America is no longer the preferred place to run capital-intensive businesses that can employ large numbers of semi-skilled workers at high wages. For a large part of the 20th century, America was the best place to locate high-tech factories. Cadillacs were built in Detroit. Now Apple iphones are built in Shenzhen.
The Americans that 40 years ago would be engaged in building and running factories employing hundreds and thousands of semi-skilled workers (requiring millions of dollars of capital), are now employing tens of high-skilled workers (requiring thousands of dollars of capital.)
In short, the capital per entrepreneur ratio in America has dropped. As a result, entrepreneurs are employing fewer people.
The Americans that 40 years ago would be engaged in building and running factories employing hundreds and thousands of semi-skilled workers (requiring millions of dollars of capital), are now employing tens of high-skilled workers (requiring thousands of dollars of capital.)
In short, the capital per entrepreneur ratio in America has dropped. As a result, entrepreneurs are employing fewer people.