Stay-at-home policy is a case of exception fallacy

"With our results, we were not able to explain if COVID-19 mortality is reduced by staying at home in ~ 98% of the comparisons after epidemiological weeks 9 to 34."

"The low number of significant associations between regions for mortality rate and the percentage of staying at home may be a case of exception fallacy, which is a generalization of individual characteristics applied at the group-level characteristics"

"In conclusion, using this methodology and current data, in ~ 98% of the comparisons using 87 different regions of the world we found no evidence that the number of deaths/million is reduced by staying at home. Regional differences in treatment methods and the natural course of the virus may also be major factors in this pandemic, and further studies are necessary to better understand it."

I am not a scientist but at least in western Europe we were not in lockdown most of the time, however the policies of wearing a mask and washing hands were applied for a much longer time than lock-downs policies. Maybe that explains why there were much less flu contamination?