Not sure where you're from, but I'm from Australia and so my experience in the 8 times I've been in Japan and 6 times in Taiwan, you don't need a car. A car can be pleasure. You can use a car, but to move millions of people a day, really good public transport is needed. Being able to walk to a interconnected grid of transport, that can link buses, trains and underground rail allows for better night life, better work balance with being able to study or watch entertainment in transit, and everything is open and accessible. Getting back to Australia with hundreds of in-build multi storey mixed commercial residential complexes but primarily cars to travel makes no sense. We have a housing crisis but no infrastructure to support the density needed where the people work and live. But a culture who remembers 30 years ago when the population density was lower, labour was more common at warehouses not as much knowledge work and were more disperse over space, everyone had backyards with hills hoists, and two car garage and a shed. Those days are gone but nobody wants the infrastructure noise or density, but it's too late. We have all that but without transport options.

Our trains are so bad that they need to be on 15 minute at rush hour intervals because schedules are hard and they'd crash otherwise. Japan has them coming every 2-3 minutes. Imagine going to the station not knowing the time table because at most it's 3 minutes to wait after work for the next one, if it's too packed, wait 2 more.

Your mileage my vary where you are, but in 10 years I can't see this population growth and density growth being solved with cars.