The reason there's so much opposition to walkable cities and transitioning away from cars is because a lot of people see all the problems with this system as good things
"car dependency reduces those who can't afford cars to second class citizens" thats the point "car dependency keeps us all distant from each other, secluded in our single family homes" that's the point
There are a lot of people who think the idea of ever using public transit is degrading, and hate and fear the idea of sharing space with anyone but especially the poor (and usually not white) people who are disadvantaged by car dependent infrastructure.
This isn't some mistake that happened just because a few lobbyists pushed for it in the 50s, its a whole model of society that a ton of people in this country supported and continue to support because it lets them feel more comfortable and superior.
This is why whenever I hear about any effort to bring public transit to my hometown of Orlando I know that shit is doomed because I know the people there are too afraid of "the wrong kind of people" being anywhere near them. They would rather live in the sprawl with their big SUVs and fuck everyone else.