And that study looked at, and the reason for surgeons wearing masks has always been, preventing BACTERIAL infection. Bacteria are much larger than viruses, and yet this study found no difference in bacterial infections when masks were not worn. If masks don’t stop bacteria then they most certainly have no effect on viruses. Wearing them to prevent COVID or any other viral infection is 100% a placebo.
As others have said, they are there to make Karen feel safe. It is also used under the pretense that we can get back to normal, and Karen can go out and go shopping like before Covid if we all wear masks. However, in practice, Karen will never do that, because Karen is still afraid of Covid and won’t leave her house.