If this peer review study is correct which covers Europe, masks are useless. https://www.cureus.com/articles/93826-correlation-between-mask-compliance-and-covid-19-outcomes-in-europe
Conclusions
While no cause-effect conclusions could be inferred from this observational analysis, the lack of negative correlations between mask usage and COVID-19 cases and deaths suggest that the widespread use of masks at a time when an effective intervention was most needed, i.e., during the strong 2020-2021 autumn-winter peak, was not able to reduce COVID-19 transmission. Moreover, the moderate positive correlation between mask usage and deaths in Western Europe also suggests that the universal use of masks may have had harmful unintended consequences.
The explanation given at https://principia-scientific.com/positive-correlation-found-between-mask-usage-and-covid-deaths/ explains the peer reviewed article quite well.
Here's a parphrasing of the principa scientific article. “The findings presented suggest that countries with high levels of mask compliance did not perform better than those with low mask usage in the six-month period that encompassed the second European wave of COVID-19,”