Masks do have their place. If you are already sick, they do help reduce the chance of spreading the virus but do not totally eliminate it. A proper N95 mask, worn correctly, reduces the chance of catching it but does not eliminate it totally. Masks also work when confronted with heavy dust and smoke. (Of course, those dumb enough to smoke cancer sticks defeat this.)
I do not like this mandatory masks, however. They carry risks in hot humid weather--if you get mold spores growing in the masks, this can create a lengthy illness that can end up worse than coronavirus. They also contribute to heat related illnesses, including a "fever" that is simply the result of not being able to lose heat in hot weather. Then you get quarantined for nothing.
The worst is that it will be continued until a vaccine, effective or not, is developed and a RFID chip is required to verify that you have the vaccine. With the 5G technology and this chip, a social score can be implemented worldwide that will make China look downright libertarian. And this will cause more misery and death than even the fear-mongerers' rendition of coronavirus as something that kills 10% of all healthy young people that get it and leaves half the survivors with permanent and serious damage (which I do not believe is the case). Communism will kill 95% of all people, including all the most intelligent. It will make things miserable for the bottom 5% that are spared. And no supplement, mask, social distancing, soap and water handwashing, or staying home will reduce or prevent you from getting this.
As for the other measures, they should be focusing on other layers. Prevention of exposure only works until the one time it doesn't, and even if you could somehow prevent all exposure to germs, your immune system would get as bored of nothing to do as teenagers that are locked in their houses. Allergies will become more of a problem. And auto-immune diseases will also become an issue. I would rather reduce but not eliminate my exposure to the virus, and then take supplements to deal with the reduced exposure. (Which does the same thing as a vaccine, with the same success rate.) These supplements would also throttle the virus if I do get infected, leading to no or mild symptoms. And, if it does get through that, drugs are the final layer before resorting to the hospital.
A mask might help. But mandatory masks are only a gateway to communism, for which a mask (or hand sanitizer, soap and water, making people suspicious of each other through social distancing which I feel will end up doing more damage than the virus could have), supplements, drugs, and hospitals will be totally worthless. Not to mention, a virus is easier on my soul than communism, even if I have a full 10% chance of dying and 50% chance of permanent damage if I survive (again, that is the extremist viewpoint).