Second, your simplistic analysis demonstrated that you, personally, are ignorant of the real tradeoffs involved in whether masks work.
Wearing a mask reduces how much virus leaves your mouth. But when you breathe out, most of the virus is in larger droplets that quickly hit the ground. However breathing out through a mask creates perfect conditions to create an aerosol, which can allow more of the virus to stay in the air for an indefinite period of time. So there is a tradeoff, and there were reasons to question whether cloth masks were better than simple social distancing.
It turns out that what matters most is not that you get exposed, but rather the initial viral load that you get. You see, the virus will go on an exponential growth until the relatively fixed time it takes the immune system to figure things out and start shutting it down. If the virus gets a solid head start, the odds of serious illness go up. Therefore the lingering aerosol from a mask is (except if it accumulates in poorly ventilated indoor spaces) of less concern than an unmasked person talking directly to you.
So the result is that masks work. Even crappy cloth masks work.
The quality of our evidence is easy to misjudge in retrospect.
The last opportunity to study the effectiveness of mandating low-quality masks in preventing community spread during a pandemic was around a century old. (Literally, the Spanish Flu epidemic.) In the meantime a lot of new and untried modeling tools were in use, as well as updated disease models, and lots of reasons to question old data.
See https://www.albertahealthservices.ca/assets/info/ppih/if-ppi... for an idea of what was reasonable for educated specialists in public health to believe. Note phrases like, "There was agreement that although the evidence base is poor, the use of masks in the community is likely to be useful in reducing transmission from community based infected persons, particularly those with symptomatic illness."
So it is accurate to say that we had reason to believe that masks work. But it is easy to overstate how much we "knew" it to be true at the time.
There wasn't poor evidence, Jesus Christ. Masks were one of the most researched forms of PPE out there, with many million man-years of practice. And the FUD about masks was not restricted to home-made stuff but any form of respiration filters.
The only reason masks were in doubt was the incompetent advice from WHO bureaucrats, and the bureaucrats on national advisory levels mindlessly droning it. This was not evidence based.
There was a ton of high quality research on high quality N95 masks. Nobody doubted that. Also, we had no supply of that.
To get everyone to mask up, we needed to put the general public in low quality masks. And there was a whole heck of a lot less research on low quality masks being used by the general public.
But, regardless, I have no percentage in convincing you of what is true. Have a nice day.
Second, your simplistic analysis demonstrated that you, personally, are ignorant of the real tradeoffs involved in whether masks work.
Wearing a mask reduces how much virus leaves your mouth. But when you breathe out, most of the virus is in larger droplets that quickly hit the ground. However breathing out through a mask creates perfect conditions to create an aerosol, which can allow more of the virus to stay in the air for an indefinite period of time. So there is a tradeoff, and there were reasons to question whether cloth masks were better than simple social distancing.
It turns out that what matters most is not that you get exposed, but rather the initial viral load that you get. You see, the virus will go on an exponential growth until the relatively fixed time it takes the immune system to figure things out and start shutting it down. If the virus gets a solid head start, the odds of serious illness go up. Therefore the lingering aerosol from a mask is (except if it accumulates in poorly ventilated indoor spaces) of less concern than an unmasked person talking directly to you.
So the result is that masks work. Even crappy cloth masks work.