Australia has a mandatory stay-at-home order, and they issued it earlier in their outbreak than we did in theirs. That explains why they're doing so well.
In South Korea they all gravitated to masks very early, and they developed enough testing capacity early on to allow contact tracing to remain viable (so far).
Australia is outside of the Covid Belt of temperatures that is ideal for SARS-CoV-2 transmission.
Australia is spared for the same reason most of Latin America, most of Africa and hotter climates in Asia have been.
Nigeria, Egypt, Mexico, Argentina, Colombia, Indonesia, Vietnam and Thailand don't have such low death rates because they've been running testing at the rate of Germany and doing tracing & lockdown & testing & quarantine as well as South Korea. It's the hotter climates. It's hot in Melbourne, Perth and Sydney during the Winter in the Northern Hemisphere, ie during the outbreak so far. Melbourne has been shielded for the same reason Lagos Nigeria has been.
Australia's measures are without question further helping to limit cases. Having a warmer climate during the outbreak time while simultaneously implementing aggressive measures, is the ideal double whammy to get a good outcome. The climate makes it dramatically easier.
> Nigeria, Egypt, Mexico, Argentina, Colombia, Indonesia, Vietnam and Thailand
Indonesia is only testing at the rate of 116 tests per million people. You only find what you measure. When the rate of testing is that low you can't make any claims about the true coronavirus death rate in Indonesia:
In South Korea they all gravitated to masks very early, and they developed enough testing capacity early on to allow contact tracing to remain viable (so far).