I fully agree with you that there is no ready or even possible short term enforcement mechanism. I also fear that politics plays a role in these decisions. I am obviously not a scientist, but I would bet a shiny nickel that when this all shakes out, those who know have made the decision that paper masks, often worn improperly and ill-fitted, have very little utility in preventing spread–as borne out by state by state data-- and that even though people will lie and get away with not wearing masks in public, the push that this will be for the middle 10 to 20 percent who are hesitant to take the vaccine will have far greater benefits than people faking it to not wear a mask.