The Japanese rail network is awesome but it does not stop everywhere and it’s quite expensive. Japan is huge and taxis get expensive real quick.
Consider Singapore, which is tiny, has a kick ass public transport system (trains and busses) and where it costs 90-100k SGD to own a beater Corolla: people still own cars.
Some people own cars. Car ownership rate is around 11% according to [1], which doesn't look that high.
That said, Singapore public transportation (at least SMRT trains [2]) is freaking strict about food and drinks. I could not even have a sip of water without triggering a warning message. So anyone who can't control their thirst or hunger (like, you know, basically any kid) isn't really welcome there.
