If you build out instead and everyone gets the SFH white-picket-fence life, the escape to nature is suddenly less important. Even if it's more expensive to connect, in the process we develop ample capacity in the commons.
Maybe it's just not possible with so much cost focus and so many competing incentives in the West. And no superseding body who can make it happen like China.
Converting 4-story to 6-story isn't really what I see pitched either, it's generally rezoning SFH/2/4-plex to 6-story+ with subsidies, which is really a huge remaking of neighborhoods.
Yes, that's exactly it!
> or because every individual is getting less and less of an overburdened commons?
No, it's not that at all. Why would common services be overburdened? Everyone still gets their water, sewage, electricity, internet, etc., but it's far cheaper to provide per-person.
And with the density you get to build public transit, so people aren't burdened by having to necessarily own a car.
Water restrictions? Fatbergs? Brownouts? Congestion? Traffic? Breathing room? Not to mention increasing demand on any inelastic local supply will drive up prices. To my initial point, the upscaling of utilities and infrastructure is often magically handwaved alongside the up-zoning demands. There are real negatives to cramming more and more people into one place!
You need to keep less $ invested in infrastructure per person if everyone lives on top of one another in a condo.
If everyone lives in a white picket fence SFH then you have to build miles of extra roads, pipes, cables. Every trip for every bus, truck, and car is a bit further.
There's a lot to be said for both rural and city life but cities can be much cheaper if there's unrestrained development.
If you had to pay the real bill for road maintenance alone suburbs would no longer be viable.
So the suburbs take from the commons and don't give back in your example.
Looking at a random SF suburb, "Pleasanton" [0] - it looks like 72% of their budget is funded through taxes and only ~7% is transfer payments.
[0] https://www.cityofpleasantonca.gov/assets/our-government/fin...
> There would be 3-4X the people, yet still the same amount of roads, services, and public utilities.
That's the point! Per capita, it should be cheaper to live in cities because infrastructure goes so much further. And if you are arguing for better mass transit, you will have to build many, many more miles if you also want to encourage people to sprawl.
Although I think the strongest case for allowing cities to get dense is it allows greenbelts and less dense areas closer to the city. You can build a big dense city UP and make it easier for people to get out and enjoy nature and farms and etc. Or you can build a city OUT and then it's just desolate city for hours around.