The real story here is that COVID is a disease that often requires hospitalization but is rarely fatal given hospitalization.

Which means that its real mortality rate is significantly higher in places with overburdened hospitals than places with spare capacity. It also means that testing early and often is very important, because the most important thing to do to lower the mortality is to slow the spread, so hospitals have enough capacity to treat everyone who comes in.

People assume that "mortality rate" is just a property of a disease, but it's not. It's as much a property of the disease response as the disease itself.