In Shanghai, you can usually get around using public transportation (bus, subway, ferry), shared bicycles (electric and non-electric), or electric scooters, these are the cheaper options. The more expensive options are using ride-hailing apps, taxi services, or driving your own car.
There are areas outside the main city area of Shanghai that resemble "suburbs" or what we call "城乡结合部", large patches of residential areas that consist of mostly one to three-story tall houses, some of the areas haven't been covered by the subway system yet. Here you can still get around using buses, electric scooters, bicycles (if the distance is short or you really want to). There are still office buildings, malls, commercial streets in these "suburbs".
China's high-speed rail have train numbers with D/G prefix, but there are still normal-speed trains with T/K/Z prefix (or even no prefix) for intercity travel.
As for traffic jams caused by cars, this is not a problem unique to any political system, it is a city-planning and engineering problem.
My opinion of cars is while they are convenient for family/group travel and carrying baggage, they take up too much space on the road and require lots of dedicated parking space. Maybe they should be designed differently in future.