“The most basic answer is because of WWII.”
Thanks for making the point I usually make in threads on this subject. The war and the geography you include in your post are lost to so many who only have the “they have it so why can’t we” thinking.
What was said also explains the German and Zjapanese economic miracles ... when they rebuilt after the war they did so with the latest technology ... meanwhile here in the States we had a greatly expanded industrial infrastructure that, while physically new, for reasons also derived from wartime priorities was also simultaneously already dated.
So the Rust Belt is what happened as our less efficient physical plants soldiered on to normal economic attrition, and even past that as the federal government and military-industrial gobbled up a lot of available Capitol, but once we took the decade and a half to retool it was American industry advancing even as, notably, the Japanese faltered.