This was not a study about transmission. And it did not just come out. It was run in April, and it was about the protective ability of masks. There were no controls, and test subjects admitted to varying levels of adherence to the protocol. 42 of 2,393 people in the masked group got Covid, and 53 of 2,470 in the no-mask group got Covid. (There weren't 6000 subjects either). But either way there is no statistical difference in these populations, and even the authors admitted that due to the lack of controls it really says nothing about the efficacity of masks as protections against acquiring Covid.
There HAVE been studys of masks in terms of fiber density and composition and all that vs. the virus size and binding affinity and you can look those up. They are scientific and controlled.
But what you misstated, and what is really important, again, about mask use IS the transmission. Or how a mask may affect the so-called R0 number. And that's a number that you won't be able to look up easily either, because it varies so much with environment. But the real thing you want to do, as a responsible member of society, is make your own contribution to keeping your personal Ro as low as possible. That encompasses several factors, but two easy ones are your social interactions and your ability to emit the virus if you get infected. If you interact with less people (i.e. shutdowns, social distancing), you won't be able to spread it as easily once you get the virus. If you wear a mask, you won't be able to spread it as easily once you get the virus. Those are the two biggies. And nobody says either of them are 100% effective either. (Well, I guess TOTAL true quarantine would be, but that's hard to do since most people get the virus before they even know they have it and so many people get asymptomatic or extremely mild symptoms, so it's not possible to truly quarantine everybody effectively in time).
Virus transmission is exponential. Just as an illustrative example, say your R0 is 3.0 (you can find a SLEW of different studies for Covid from basically 1 to 6, but those all essentially come down to environment). We won't ever have a real single number on it that applies equally to everybody everywhere at all times. But say it's 3.0. In that case, within 3 incubation cycles, a person infected with Covid would normally spread the virus to 40 people.
Now suppose instead the infected person wears a mask whenever out and about, and that is NOT perfect, but suppose it reduces the R0 from 3 to 2 in your environment, thanks to the mask blocking some of your virus output. You think, wow, that's not super effective since you still infect 2 other people instead of 3. That's hardly effective at all! And yet, over 3 incubation cycles of a mask-wearing population, only 15 people in total get infected.
People need to stop thinking in absolutes, and just get on with doing your part. Yes, nothing is perfect. But these things add up quickly. Again, I'm not saying these are the exact numbers, they are just illustrative examples. You can Google 20 different results. And what your media is going to do is cherry pick the result that gives you the answer you are already looking for. So yes, you WILL find an article that says Ro is not affected by masks. Bogus. And you WILL find an article that says Ro is 1 and one that says it is 5.7 and again, they have limitations. But the underlying principle is what matters. A mask WILL have an effect. It is not perfect, nor is it well quantified yet. But do you want to have a positive effect at limiting the spread of the virus, at whatever level, or don't you?
