Cars are by now a hard to reverse environmental and urban planning disaster across the world. We are stuck with them. As a mode of transport it has grown uncontrollably at the expense of all others (except the airplane) and practically everything has been shaped to accomodate it.
Reversing that development, limiting car traffic to where its really needed is like trying to perform a complete heart and arteries transplant on a living person. Even if there was a will (which there is not) it is not clear if there is a way.
In the best scenario it will be an excruciatingly long transformation (~50 yr) as car oriented cities (or city sections) get slowly deprecated and the car-free or car-lite segments become more desirable, more livable.
I've lived most of my life in former streetcar suburbs -- neighborhoods of single-family homes, duplexes, and small apartment buildings that were served by a streetcar line every few blocks. Today, some of those places require cars to get anywhere interesting and back, while some of them have a few well-used bus lines and a ton of local restaurants, groceries, and hardware stores in easy walking distance.
The density tipping point is really low; a few four-plexes on each block, which didn't diminish any of the "neighborhood character" or lead to epic struggles to find parking. (I did still have a car, I just used it a lot less, and was much happier not having to bother.) And it felt a lot nicer than the all-or-nothing neighborhoods that are either single-family homes or large corporate apartment complexes.