I think this is too narrow of an assessment. More common in America than single adults living alone are two adults living together, with each having their own car. So while you’re right that the present American land-use reality isn’t exactly conducive to having a plurality going car-less, it’s entirely probably for a couple to save substantial money by switching one car for a bike and keep just one car for the household. That’s something that can apply in huge swaths of the country, although it’s exceptionally apt for cities.