This fact is unpopular following the use of this older report by the CDC which seemingly showed a small impact of the mandates.

The study on the impact of national face mask laws on Covid-19 mortality in 44 countries with a combined population of nearly a billion people found that—over time—the increase in Covid-19 related deaths was significantly slower in countries that imposed mask laws compared to countries that did not.

Average COVID-19 mortality per million was 288.54 in countries without face mask policies and 48.40 in countries with face mask policies. In no mask countries, adjusted average daily increase was 0.1553 – 0.0017 × (days since first case) log deaths per million, compared with 0.0900 – 0.0009 × (days since first case) log deaths per million in the countries with a mandate. Sixty days into the pandemic, countries without face mask mandates had an average daily increase of 0.0533 deaths per million, compared with the average daily increase of countries with face mask mandates, at 0.0360 deaths per million.

This study's significant results show that face mask mandates were associated with lower COVID-19 deaths rates compared with countries without mandates. These findings support use of face masks to prevent excess COVID-19 deaths, and should be advised during airborne disease epidemics.

www.ajpmonline.org/article/S0749-3797(21)00557-2/fulltext