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.