That's what happens when thanks to Henry Ford every middle class American could afford a car by 1940. It took Europeans another 30 years.
(My brother lives in a 1926 apartment that is 10 minute walk from the beach. Although that privilege does come with a 460k price tag. Nobody had a car back then unless they were millionaires so the entire area was built with trams, bicycles and walking in mind).
The car affordability can't explain it alone, since European cities/towns don't really suffer from these problems. Density is higher, sidewalks are everywhere and American style suburbs are quite rare.
(OTOH there are other problems, many people live in tiny apartments)
(My brother lives in a 1926 apartment that is 10 minute walk from the beach. Although that privilege does come with a 460k price tag. Nobody had a car back then unless they were millionaires so the entire area was built with trams, bicycles and walking in mind).