Why all the time? Can't we identify conditions where flu is most likely to spread and encourage mask wearing specifically in those situations? When things are b

Why all the time? Can't we identify conditions where flu is most likely to spread and encourage mask wearing specifically in those situations? When things are back to normal I will probably still wear my mask on the subway for example, especially during rush hour in the winter. But walking around outside I would feel no need. I'm not sure exactly where the right balance would be as far as public willingness versus effectiveness in preventing spread, but it's definitely not going to be "everybody should wear masks all the time".