I read that South Korea has provided the best testing regime of all affected countries - even making stuff like drive through tests available.
I don't know how quite how this would have affected the death rate (or at least the death given infection rate), but I understand that they were able to track and slow the spread very efficiently, even without mass lockdowns.
This seems the best explanation. A better funded, less overrun healthcare system that has the capacity to test more widely, stop the spread and provide care earlier would logically reduce the death rate.
I read that South Korea has provided the best testing regime of all affected countries - even making stuff like drive through tests available.
I don't know how quite how this would have affected the death rate (or at least the death given infection rate), but I understand that they were able to track and slow the spread very efficiently, even without mass lockdowns.
Article here, there's likely better ones available:
https://edition.cnn.com/2020/03/09/asia/south-korea-coronavirus-intl-hnk/index.html