It happened because of 75 years of industrial growth, American inventors, American tycoons and bankers taking risks, millions of immigrant laborers and farmers to feed them, conflict and violence, several Panics and one Great Depression. After the second war we rebuilt Europe, continued arming our military and fostered the rebirth of Western Eurpoean industry as an ally in the Cold War. All the while we made money and built more factories but prifit is the god of capitalism and cheaper labor means greater profit. Unions had raised wages at the same time as allowing workers to buy the products they made,buy that house in Levittown, send their kids to college. International competotors arose, first Japan then Western Europe. It was competition . We beat Japan but others arose. Now we assemble, we don’t make and tge infrastructure needed to return will take longer to build than Pres Trump has left in office.
It happened because US retailers markup 1000% and they expect the manufacturers to make product without profit.
That last is why MAGA cannot end with Trump. It is why we need a JD Vance, someone not beholden to Wall Street, who understands middle America and will fight for them.
A lot holes and miststakes in you analysis.