China has child labor.
As well as 12 hour work days, roughly $1.68/hour minimum wage, no health regulations, no health benefits, no pollution control (16 of the 20 worst polluted cities are in China). It even engages in prison labor where prisoners don’t eat unless they reach a product quota.
China makes products for cheap.
The U.S. has overtime, minimum wage of at least $7.25/hour, health codes, health benefits, zoning requirements, building codes, and pollution regulations.
It costs to maintain regulations. The U.S. can’t make products for cheap.