Masks cover the primary communicative tool of societal interplay. They are a major step toward anonymous discourse in which no one is responsible for themselves.
They also obscure facial expression and provide an image of fear and repression. Being gagged or muzzled has never been considered to be a good thing. It usually means that you’re being held prisoner.
There are masks with “windows” over the mouth. These were originally developed as an accessibility measure for deaf people, so they can read lips of their hearing friends/family. Also, there are clear face shields with cloth around the edges to enclose the face and provide filtration without obscuring features.
You can still see people’s eyes above the mask, and some expression.
I read somewhere that the practice of covering your mouth when you sneeze or cough is a legacy of the 1917-1919 influenza pandemic. Perhaps wearing masks in public will be a legacy of the Covid-19 pandemic. As we’re taking half-hearted measures to stop the spread, that outcome (of mask wearing culture) is becoming more likely.