I am genuinely curious if the Sydney and Melbourne metropolitan areas are "considerably denser than US equivalents."
Wikipedia has the Sydney metropolitan area with 5,297,089 residents within 4,775.2 square miles. That is a population density of 1,120 persons per square mile. Meanwhile,
Wikipedia has the Melbourne metropolitan area with 5,031,195 residents within 3,858.3 square miles. That is a population density of 1,304 persons per square mile.
So for comparison's sake, what are the "US equivalents" to the two most populous metropolitan areas in Australia? The two most populous metropolitan areas in the US?