I'm already paying an order of magnitude more for the same facilities I'd get in states that are less dense than California.

At least out here, things are so screwy that minor details like cost of materials are rounding error.

Will happily pay for atmospheric carbon recapture, which covers the biggest externality.

Also, like most other commenters from the west coast, I'd live in one of the cities if they weren't littered with human waste, and if they had reasonable public schools.

How is paying property tax free-ride?

They are referring to sprawl externalities. Strong Towns delves into this (and they have some points, but are also overly pessimistic about suburban and rural costs).

https://www.strongtowns.org/the-growth-ponzi-scheme