I agree. you can find a scientific study to support just about anything you want.Both the "no HVAC" and the "lower life expectancy" theories for why COVID didn't wreak carnage on the populations of 3rd world countries have equal validity.
That is, they are both purely speculative. I suspect that in both cases people with an agenda can find some data somewhere to support but not prove their respective hypothesis, but the real reason may never be known.
Africa’s low COVID-19 mortality rate: A paradox?
COVID-19 continues to spread worldwide, with high numbers of fatalities reported first in China, followed by even higher numbers in Italy, Spain, the …
www.sciencedirect.com
"Africa’s lower COVID-19 mortality rate is due to the lower population mean age, lower life expectancy, lower pre-COVID-19 era ‘65yr+ mortality rate’, and smaller pool of people surviving and living with cardiovascular diseases."