License requirements can’t be strict unless the infrastructure makes accommodations for people who fail. The US is so car-centric that driving has to effectively be an entitlement, even though it’s supposed to be a privilege, in order for people not to be stranded at home.
It’s easy to understand once you realize that the secret ingredient was racism.
Basically, it’s because of a combination of mid-century modernist utopian urbanism (a big influence was Frank Lloyd Wright’s “Broadacre City,” which was really closer to the opposite of a city) and the effort to find new ways to perpetuate racism despite SCOTUS outlawing de-jure segregation.
More specifically, the newly-created FHA came up with preferred development patterns that were low-density and car-centric in part because it was expensive and therefore helped exclude black people, then redlined everything that didn’t conform to that preference in order to deny black people financing for their homes and businesses.
(This reply lacks a lot of detail and nuance, mainly because I’m writing it on my phone and lack access to references to cite.)