You're friend might be wrong.
Sometimes people only believe what they want to believe.
Anything that goes against what is believed tends to be ignored by them.
Science Brief: Community Use of Cloth Masks to Control the Spread of SARS-CoV-2 | CDC
At least ten studies have confirmed the benefit of universal masking in community level analyses: in a unified hospital system,42 a German city,43 two U.S. states,44, 45 a panel of 15 U.S. states and Washington, D.C.,46, 47 as well as both Canada48 and the U.S. 49-51 nationally. Each analysis demonstrated that, following directives from organizational and political leadership for universal masking, new infections fell significantly. Two of these studies46, 47 and an additional analysis of data from 200 countries that included the U.S.51 also demonstrated reductions in mortality. Another 10-site study showed reductions in hospitalization growth rates following mask mandate implementation 49. A separate series of cross-sectional surveys in the U.S. suggested that a 10% increase in self-reported mask wearing tripled the likelihood of stopping community transmission.53 An economic analysis using U.S. data found that, given these effects, increasing universal masking by 15% could prevent the need for lockdowns and reduce associated losses of up to $1 trillion or about 5% of gross domestic product.47
https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/masking-science-sars-cov2.html