>> “Viruses are 250 times smaller.” <<
But are virus particles typically alone, or clustered in larger droplets of moisture?
Makes no difference. The droplets may be slowed down, but eventually they are inhaled and at some point exhaled back out.
Masks are bacterial concentrators and they will concentrate but not stop viruses and droplets.
Look at what they are wearing in a virus isolation room or lab. It isn’t masks, it is a full up, sealed, bio suit.