Compared to umbrellas, masks incur much lower extra costs and inconveniences. Even more importantly, we can almost perfectly predict if it will rain or not, wit

Compared to umbrellas, masks incur much lower extra costs and inconveniences. Even more importantly, we can almost perfectly predict if it will rain or not, within a day or two, and especially in US, there is no much need for umbrellas anyway - get a plastic bag and run to your car. Masks are also culturally acceptable right now.