Right, there's no doubt that this is how American cities are organized today. What I'm advocating for is allowing that to change naturally over the course of a few decades by upzoning urban lots to allow for more density (everywhere, but especially near transit). As traffic increases in the denser zones, more people will choose to live there to avoid the commute (and because we know humans choose to move to densely-developed neighborhoods when they're allowed to), which generates even more density, and so on.
The status quo today is that these alternatives are illegal in most parts of most cities.
I think the rub is that what you propose is not politically feasible. It may or may not be objectively a great idea, but we live in a democracy and the moment you do something overtly that causes pain for enough of the voting population to matter, they will just vote in a different politician who will reverse the policy.
Yes, I'm very pessimistic about democracy's ability to address the most important questions of our age. We're paying an enormous productivity price, locking young people out of access to the best places to live, and we're dealing with it on a timeline that's totally unresponsive to the scale of the problem. And what's so maddening is that it's a totally invented policy problem.
The status quo today is that these alternatives are illegal in most parts of most cities.