> Over a few decades the availability of cars naturally destroys the usefulness of other modes of transportation unless there is active effort to prevent these effects.

That is simply not true. The car isn't some inherently superior mode of transportation. People will use whatever infrastructure a city invests into most. If you build a city where all the infrastructure budget is spent on cars, then is it any surprise people will use their car to get everywhere?

Once you force people to use cars to get anywhere, then of course that kills local shops, but that didn't happen simply because of the availability of cars. It happened because the city stopped investing into any infrastructure that's not designed for the car.