However, each person who uses a car creates some external costs (a high traffic factor / unit of person-flow) which are borne by all the other road users. Once people choosing the "defect" strategy (cars) have enough numbers, the "cooperate" strategy (not cars) gets broken for other solutions that use the road network, so the system fails to a bad equilibrium if there are enough defectors in the population.
(I'm not a fan of cars; I don't drive one myself. But I don't expect people to accept any less convenient and flexible solution.)
There are a number of US cities that get most workers into the urban core besides NYC despite poor to middling infrastructure at best, but driving infrastructure dwarfs everything else, bike lanes are added only to diet roads usually (resulting in shitty lanes), and most areas see 60% to 70% of their land tied up in (mostly empty) parking, which is a disaster for every mode of transport.