Also US cars were genuinely horrendous in the 80s-90s in terms of build quality & reliability vs same price or cheaper Japanese equivalents.

It's only rather recent that all the big name car makes from US/Europe/Japan/Korea are pretty good & reliable. There were huge differences 30-40 years ago.

I think there's a finer point here: US consumers don't want to pay for local UAW labor. GM&Toyota did fine out of the NUMMI plant, and companies like Nissan and Mercedes are making cars in Alabama.