Don't focus on the actual effectiveness of wearing masks. Turns out that they are not all that effective for health care workers, who have years of education and socialization about proper isolation discipline. Masks are really annoying, and the whole ritual of donning and doffing is tedious, so lots of HCW are sloppy. Civilians using masks will be even sloppier and less compliant.

But wearing masks is a virtue signal. If you have a mask, you are conscious of the risk of infection and are doing your best to protect yourself and those around you. It's like asking a new acquaintance what their pronouns are, to avoid offending the non-binary gender-fluid by imposing your hetero-normative gender bias upon them.

It's like gang colors, or a tactical backpack, or driving a Jeep: makes you look like one of the cool kids, even if you haven't done the work of being cool.

Lots of the public health advice has a blend of science and social psychology influences: note that the CDC now recommends re-use of disposable masks, use of outdated masks, and substitution of field expedient masks like bandannas for HCW who cannot access N95's. If their surveyors had found me doing this in my ER, they would have cut my parts off.
Which might have changed my pronouns.