A big part of the problem with cars is that their existing infrastructure is already very expensive to maintain and promotes other utilities such as electical lines and water lines to be longer and therefore more expensive as well. After initial investments most transit and active transportation ends up costing less to maintain per trip than car infrastructure. Currently much of car infrastructure is heavily subsidized.

I think there would also be issues with a significant portion of the population not wanting to adopt a subscription based service over private vehicle ownership.