Germany had a N95 mask mandate (called FFP2 in Europe), nothing else was allowed, and yet had a very similar infection curve to Sweeden (according to article picture) which had no mask mandate.
Mask quality is definitely a factor, but can't be the major factor, unless people wear masks 100% of the time and never take them off outside of the house, which we know it's not true. There is also the "eye protection" factor, which seems to exist.
We know it helps doctors as doctors had lower rate than general population in USA and we also know severity of case is linked to severity of exposure.. so it’s safe to assume masks have helped a ton
Mask quality is definitely a factor, but can't be the major factor, unless people wear masks 100% of the time and never take them off outside of the house, which we know it's not true. There is also the "eye protection" factor, which seems to exist.