I feel that you do not understand, not even the articles that you link to.
> You're just wrong about San Fransisco's population density being low. It is 21st most populated place per square mile in the U.S.
21st is far below 1st. Also, dividing by city is arbitrary and misleading, because a lot of traffic moves across the entire region. As a metropolitan area, San Francisco is 7th in the US, at only ⅓ the density of New York. And the density is even worse when you consider that it is unevenly distributed, and also when you compare to other metropolises around the world. It’s denser than the typical suburb, but it is still not dense enough. This low density contributes to the traffic problem.
I am going to ignore your ad hominem straw man about induced demand. I even linked to other sources that discuss the same issue. It’s not a marginal idea.
> Being more distributed reduces the need to transport water (arguably the single most important resource) vast distances.
Being distributed would reduce infrastructure if you didn’t have to connect them. If you draw your water from a cistern and flush your toilet into a septic tank, then you don’t need vast pipes. That is not suburbs. As far as I know, the typical suburb requires the centralized systems of a city, but uses more pumps and a lot more pipe per capita to bring the water to the residents. So much that the equipment just can’t be maintained using taxable revenue. [0] We need greater density to decrease per capita public expenses.
> Not to mention, suburbs eventually becoming cities (or as populated as such).
That doesn’t automatically happen. You have HOAs that fight to preserve some unrealistic ideal. You have NIMBYs who say growth should happen but it should not happen here. You have zoning laws that make it illegal to put jobs and grocery stores in walking distance of housing. We need to recognize that the suburban lifestyle is an unprecedented disaster, and work to undo that mistake.
> My argument was that the suburbs have access to at least just as much as a city, at a more affordable price.
My argument is that there are other considerations, agreeing with aaron695 that “very high density where people live is the most important thing ever.”
I also disagree with your numbers, and I could play soccer, go mountain biking, and go to one of a huge number of stores and restaurants in one day, without even leaving this city, because it’s not spread out over a vast area. As a bonus, I also avoid trampling the road with a multi-ton death machine and spewing noxious gases into the air I breathe, because I can do all that without driving.
“Affordable” is a weird issue. As SonjaKT has pointed out, the price of housing and the cost to produce it are not directly connected. The bigger issue is that suburbs are not sustainable.
[0] http://www.strongtowns.org/the-growth-ponzi-scheme/