You can have that. A freestanding home in a quiet neighborhood with a garden and space to park one car per family with affordable housing and high quality transit in reasonably dense urban development (150+ density, 2x that of the city of San Francisco) is possible. And it scales to millions of people, even tens of millions. But you need Japanese street geometry. That means small blocks and really narrow streets. Really narrow like 4-5m wide streets making up 80% of all street kilometers in your city. That's 4-5m building line to building line with no sidewalks because the entire street has to be shared.

It works, but it's no good for daily driving. You can get out of town in a car with some patience, but you're going to take the train in town.

If you can accept that, you can have it all. But no American city has made that choice.