All of that being true, I would like to add that in pursuit of being rational and scientific, I would really like to know to what fraction of spread of virus is

All of that being true, I would like to add that in pursuit of being rational and scientific, I would really like to know to what fraction of spread of virus is affected by any measure that we take (here: wearing masks, when we wear them or where we wear them). For me it's a matter of satisfying my scientific curiousity. Of course one shouldn't stop taking those measures seriously in that pursuit.