Earlier quoted context omitted.
Australia counts 0.1% of the population as infected while the US counts 2.4% of the population as infected. Where in the study did they control for that when looking at the mortality (which is counted per population and not per infected)? EDIT: My point is that the epidemic is not over yet and countries with a low immunity could be hit harder later on. It's just too early to compare mortality numbers.
Why would you want to do that? At the end of the day, successful pandemic response is a question of how well you prevent deaths overall, not how likely infected people are to die.
Though, I'm not sure that was the GP's intention.