The mask serves as a reminder to avoid touching your face without cleaning your hands,
All other functions are secondary.
I'd say there's a continuum of effectiveness. wearing a mask wrong is still helpful. wearing an n95 mask properly fitted and sealed is still not a 100% guarantee of keeping out the virus. I'm glad people are wearing masks, but I agree, they could put a little more effort into it
I see lots of people wearing masks. If you watch them for any length of time 99% of them aren't wearing or behaving correctly with them. Lots of websites out there and directions on purchased masks that tell you how to wear them correctly. Seems very few are paying attention. It's more of a fad to many than a real way to control a virus. IMO.
But the throat and lung moisture particles expelled during coughing and breathing, upon which the virus travels through the air, are large enough to be stopped by an N95.
You aren’t trying to keep out individual viruses. The danger isn’t loose viruses just blowing around in the air. You’re trying to keep out viruses suspended in respiratory droplets.