So we should all pile into cities? Do you realize how ridiculous that is? We can't concentrate everyone in a walkable / bikeable area, it's just not feasible.
Most people? Sure. It requires re-thinking how we (Americans particularly) structure our cities, and will not be an overnight process, but what is preventing us from doing this generally? Aside from the idea that such re-thinking is impossible, anyway.
The fact that people don't actually want to do that? People are free to live their lives the way they want. There's no reason to pile most people into cities just "because cars"
Or, put more bluntly: why must I and my children pay for them?
Because uh. That's literally sociopathic.