In the 1700's, over 90% of the population was engaged in growing food. Then things like motorized tractors made farming so much more efficient that one farmer could produce more food than 20 of his ancestors could. So what happened was that people figured out OTHER things that could be produced that customers would be willing to buy.
When making a given product becomes more efficient through automation, it means that people are freed up to make other products -- except when you change the environment to where ALL manufacturing has to go to China, because of domestic regulations from EPA, OSHA, EEOC, etc.
I do believe the current estimate is that only 2.4% of all products sold in the USA are made in China.