We all wear masks for the same reason we all wear pants.

The odds of someone running commando under their pants is very very low, and so the vast majority of the time the pants are just a courtesy/custom. But every once and a while they perform a much greater function (dude with no underwear in his life) and for that we are all grateful for the custom of wearing pants in public.

It is nothing more than that.

Pants are not a political statement. I do not rate my Uber driver based on pants vs shorts. I do not rate Starbucks on the type of uniforms (or not) it makes the barista wear. I general not not give a damn about the attire of people if it is reasonably professional or appropriate in the context of our interaction. And that context has now change to make masks like pants: a common courtesy, a new custom, and something that is occasionally very necessary.