With the majority of the population living in cities on the coast. Sydney? Melbourne? Big, dense cities. We're not all out living in the bush shouting cooee at each other.

If you measure average population density across the entire country, sure, but the vast majority of the country is practically uninhabited.

Sydney and Melbourne are much like any other large city in the world and, at around five million people each, combined they represent ~40% of the country's population.

The early success Australia saw in dealing with this pandemic had nothing to do with sparse population.