How do you economically electrify all those those evenly-spaced 7-acre plots of land? How do you build roads to all of them? How do you deliver mail to all of them? How do you get water and sewer lines to all of them (wells don't work everywhere, and septic tanks pollute and just generally suck)? Hell, what company is going to lay down fiber or even coax to all of them? How do you build grocery stores such that people don't have to drive 90 minutes to get one, but there aren't so few customers per store that most of the produce spoils before it can be bought?

I know you're exaggerating for effect, but every degree that you spread people out means greater and greater investments in infrastructure and utilities you need to build and maintain, and some things we take for granted today just become infeasible.

And I agree that it's ridiculous to pay $1,000 per square foot (or more!) for housing in San Francisco. But that's not because of some sort of natural consequence of things, it's actually because it's not dense enough, and the political will to force more building just isn't there. Housing is so expensive here because, despite all the bad things about the city, despite the alleged COVID exodus, we still have far far more people who want to live here than the available housing can support.