The effectiveness of the propaganda has been astounding - of course they are underestimating it, they were convinced that masks didn’t work to avoid wasting them, just as they were convinced that a 15 day window would flatten the curve.
And, no one thought masks didn't work; the guidance was "don't buy the masks that work because health professionals need them, and you can achieve the desired effect by keeping distance".
Now there is some thought that maybe, MAYBE the virus can stay airborne longer than thought (no proof of that; we have yet to see any infectious agent actually do that, even in a lab), and that maybe, MAYBE a non-medical mask can help a bit if that's the case, so sure, why the hell not, wear a mask, but not a medical grade one, please, we need those for our doctors and nurses.
There were actually several high profile experts around the world (WHO, US Surgeon General, most European authorities, even children's programmes) that said without any qualification:
"Don't wear a mask, there is no need to wear mask if you are not sick, in fact it may even be harmful and may create a false sense of safety.".
This was a harmful and factually false message that caused and will cause unnecessarily deaths and those who propagated it should be held accountable.
Even that statement you know was qualified, since I'm assuming you aren't implying it was to practicing medical personnel.
"There is no need" - there still isn't. There are zero instances, even in a lab, where we've seen the virus aerosolize. If you keep your distance, all indications are you should be fine.
The only thing that has changed (and remember, this is advice based on facts, and so as new facts are uncovered, the advice can change too; that's called "science", and is different than "propaganda", which is what I was directly responding to) is that we have seen some cases we can't explain...and so the guidance has become "just in case, sure, why not...just please not the medical ones because we need those for people who have to get within 6 feet of sick people".
I disagree that for the general public there is no need to wear masks. If you go to a supermarket and someone sneezes/coughs at you, even a scarf around the nose gives _some_ protection. Less than perfect, but more than nothing.
A proper mask would give more protection. The fact that there are not enough masks is a different issue, but it doesn't mean they are not needed.
I don't need any evidence or data for this and I don't need to have a theory of aerosoles to understand this, as it is common sense, and there is zero downside to do it, so it is a no-brainer.
But if I still needed data, I could look at which countries have the most widespread mask-wearing among the general public: Japan, SK, Taiwan, China, HK, Singapore. Basically, all the countries that managed to contain the epidemic with reasonable success. When the top Chinese epidemics/virology expert was asked in an interview what Europe and US are doing wrong, he said if he had to mention one thing, it would be lack of masks.
