There is no absolute need for a car in China, it a convenience not a necessity, like somewhere in Phoenix or Tampa. So even if China twice GDP per capita compared to US there is still would be less ownership.
You may have to define "need". It is likely possible in nearly every jurisdiction to live without a car - particularly large cities like Phoenix or Tampa. Still I wonder why "living without a car" is really that important of a goal. Making life as awesome as possible should be what we are really shooting for. Being a 5 minute walk from everything important would be great. I don't know about a 15 minute bike ride though - that is really quite far and most people would probably rather drive I think (especially if in a hurry).
