Yet … the crowded areas are crowded because they’re desirable. After they become crowded, public transport and biking (interesting things are close enough to bike to) become practical.
Goes for North County coast, Pacific Beach, San Francisco, and Manhattan just the same. If the younger generation wanted to live in suburban subdivisions, they’d do so. Most Americans don’t move to the cities and coastal areas for ecological reasons, but because living there is fun and interesting.
If the Chinese were smart, they’d build their infrastructure from scratch to be comfortable AND green. Hydrogen and electric cars, powered via nuclear and renewables, for one thing.