True, but no one uses them properly.
For example, once masks have been worn over a half hour, they start to dry out and release any virus they might have filtered out as a saliva droplet.
I also have never seen anyone sneeze into a mask, and they all pull it down.
Oh tell me about. I’ve witnessed several people defeat the purpose of the mask by removing it just before they sneeze. Your right about the amount of time also which is why making kids mask 6 hours in school is just ridiculous. They can take it off at lunch anyway. It’s just common sense that seems to have eluded most people in a position of power.
So in regards to the OP the masks do work if used properly in the right setting, but as you pointed out masks are not used properly.