OK? So a mask can block a sneeze or cough. That is not really a revelation.
The issue is that asymptomatic people are not coughing and sneezing. If they happen to be infected and able to spread it, which has not been proven BTW, they will not be shedding virus in droplet form (ie snot). The virus they would be shedding would be individual viral particles, also called dry shedding.
Those individual viral particles are invisible to the naked eye and can sail right through ALL masks except the respirator types that look like complex gas masks.
So, if you are snotting, sneezing and couging, you should either stay home or wear a mask and go to the Doctor!
If you are not doing the above, you should not be required to wear a mask as it would not do anything anyway.
And, if you happen to have to sneeze or cough and you are not wearing your mask, do it into the crook of your elbow. In other words, cover your face at that point.
I get a kick out of those that are making the videos like the ones above. They show a sneeze or cough and the spray from it. What they do not show is the individual microscopic particles that were unhindered and sailed right on through that mask. Hint, you need an electron microscope to see the ones in the virus size range.
But, masks make people FEEL better so there is that.
Keeping away from crowds and keeping ones distance is far more effective than a mask.
Also, when you wear a mask, and you are not doing it properly I can bet, you are actually putting yourself more at risk. Masks were designed for semi-sterile environments where one washes their hands before donning the mask. They then remove and dispose of the mask using the procedure that is proper for the specific mask they are wearing. They then wash their hands again.
But, for some reason, people have been led to believe that wearing a mask in Wal-Mart, putting it on right at the door and removing it to shove in their pocket upon exiting somehow helps. It don't. You just contaminated everything if anything happens to be on the surface of that mask. Your hands, that you are now touching your face with or eating your fries, are contaminated. Oh, and that itch you just scratched on your nose allowed whatever was on your mask to get in too. When you take the mask out of your pocket, everything it has touched is contaminated.
If by chance you managed to remove your mask and hung it up, it will slowly dry from the moisture in your breath. As it drys, it releases any viruses or other contaminates that are in it. If you put it back on, you will be breathing those in. This is why health professionals don a new mask for each patient and each time they leave a contaminated room.
I can go in to much more detail if you wish. I was the Infection Control Officer in my unit for about 5 years. I updated the books and conducted training on the issues, especially with masks and PPE. As such, I went to school for the issue and received yearly updated training.
But, they have let this horse out of the barn and now they have to run with it, because we know the government NEVER says that they were wrong.