I can't buy it, European citizens almost all have to wear masks and we can clearly see that this measure alone doesn't seem to have an impact on the epidemic as the speed of the increase of cases is more or less the same that what we had in march. And nobody was wearing masks at that time.
This post links to an article showing masks don't work (N95 masks that are worn properly do work, though).
"The Most Masked European Countries Have the Biggest Coronavirus Surges"
https://www.frontpagemag.com/fpm/2020/11/most-masked-europea...