The main issue is people want to copy Japan by building high speed rail, but Shinkansen isn’t actually that useful - it doesn’t carry mail/cargo, can’t carry much luggage, and though pleasant to use it’s quite expensive. It’s closer to business class flights than anything else. Economy class flights inside the country are often actually cheaper if you don’t mind going to the airport.

Japan’s strength is that you can take yourself everywhere daily on a train or walking/biking, and there’s density and malls in the train stations.