I read back in the late 70’s that it would have been cheaper and made more economic sense to shut down Detroit and re-train all the auto workers than to subsidize a group of dying companies
But that was not socially or politically feasible. America was based on the idea that you did not need a fancy education: you just went to work, learned a specific job, did it well, gained seniority and you could live well, own a house and car, and maybe even a boat or a vacation home, and even put your kids through college.
DT won the Midwest and Middle America on the empty promise of bringing those sorts of jobs back.