The strongest case for urban density isn’t aesthetics, it’s math

> You can house, at most, the number of people you build homes for. The more homes you build, the more people can afford to live in your city.

One problem is some people owning multiple homes and blocking them from long-term use by making those buildings short-term/vacation rentals. This is where regulation makes sense to me, and one of the many purposes a central government can serve. This is assuming a government (of people) that cares about the well-being of all inhabitants.

Maybe I'm misunderstanding something about the author's overall point here, but what is it that actually should matter? Is the most important thing on Earth objective mathematical efficiency or subjective quality of life?