You can wear any old rubbish on your face and that satisfies the anxious. The reusable floral masks my family have on examination are useless. The blue paper ones I wear at my new job post airline are uncomfortable, get all fluffy after a few hours interaction with my stubble, and the fibers send me into coughing spasms by the end of the shift. (They’re gonna be super uncomfortable when it gets hot and humid in summer)
IMHO its just being seen to do something which makes some people feel better than doing nothing at all. (Like taking a pic of the tracing poster on the shop window even though you don’t have the tracing app because you don’t want the politburo knowing where you go and what you did any more than they already do)