Masks used for this particular purpose aren't very effective.
Cotton, polyester non surgical masks are harmful and aren't effect barriers.
Actual surgical masks are effective in certain situations in controlled environments....like an OR. 99% of people will touch their mask, reuse it, set it down, drop it....wear it for a few days at a time....where it in a bathroom (you like breathing in fecal matter all day?)
It's more psychological and gives the those in power the feeling of control. A lever to pulled.