The magic property is likely the fact that In certain healthcare scenarios such as clinicians performing surgeries, reducing transmission of virus and bacteria can save a patient who might be immuno-compromised or on immune system suppression drugs.

Taking The criterion needed for sterile facilities due to very specific and well defined purposes and applying it broadly in other scenarios is largely ineffective at best, and malfeasance at worst. In fact, I'd say most of these individuals are doing this for the social media value whereby it turns into group virtue signaling or for collective shaming and drone control.

Speaking from an evolutionary biological perspective, the idea that people are wearing masks in many of the scenarios is a tragedy in the making, not this tone because the virus is not lethal. Exposure by individuals leads to herd and group immunity. In fact, surviving with the virus is one of the surest ways to increase the overall fitness of humans. This should be mandatory, especially in light of data and evidence that suggest for those under the age of 50 with no co morbidity, this virus is almost as deadly as the flu.

The fact that most people don't operate in such sterile environments is one particularly good reason to avoid the masks. Adults exercising, biking, walking hiking etc leads to them repeatedly touching and readjusting the mask. I've never seen any of these adults use alcohol prep pads on their face and hands after adjusting it, while outdoors exercising or while walking around inside places such as home goods stores.

But, as you have already surmised and are quite well aware of, the masks are really for virtue signaling and social control by particular groups and particular people. Groups that want you to not wear a mask when it may make you feel better because they tell you not to be preset of some collective.. And Groups that say you need to wear a mask, if you don't you hate science, people of color, and you want to kill old people.

As a libertarian, i think people should be able to wear masks add they see fit. I most certainly don't think the government should be mandating it. I mean covid isn't even considered at epidemic levels, and jammy been since early June, but you won't hear anything about that. I don't swear a mask, unless i know I'm around a particularly at risk population, and even them, it should really be them wearing a mask, not me. But i do enjoy it when i get approached about not wearing a mask.. Freedom is hard, and telling someonethat they aren't important enough to save over the species is hard for some to hear, but I'll keep saying it.