The masks may have had some benefit. The severity of Covid seemed strongly correlated with initially viral dose. Combined with fairly severe isolation some people may have been spared the worst of the disease. That would exclude anyone spending time in an enclosed space with an infected person or most people who had to work. Single people or couples with no children or other visitors not living in apartments may be an example assuming they didn't spend long shopping or other activities like medical visits.

I recently had an experience that shows how bad those normal masks are. I had a bunch left over and used one to cut up an old woodstove to get it out of my house. I only made it for about an hour before I had to quit. My sinuses became coated with the black dust from the abrasive cutting blades and it was hard to breath. Got a cheap respiratory and couldn't even tell I was working with abrasive dust.

depends on what application a given person was using the mask for in the first place. I mean if a person wanted to prevent getting a gnat getting sucked up a nostril...then I would say that a mask like this about be quite sufficiently effective for that...right?