we are mandated to here- (although law enforcement isn’t too oppressive about it)- and again- if it stops covid from going out- then it stops covid from coming in- these aren’t one way only masks- Studies are showing masks are significantly stopping virus from getting through to the other side- regardless of which side- This is why doctors and nurses etc wanted them- because they help protect the wearer too- provided you learn not to touch your face, and remove them safely- if there’s any evidence to contrary, I’m not aware of it- but common sense suggests that it stops virus from entering and from exiting-
And yet many N95 masks have an exhaust valve, so they filter nothing going out.