I can provide only one data point in favor of wearing masks. My son is a paramedic who has hauled many COVID patients since the beginning of the pandemic. Most trips resulted with him in the back of an ambulance with the patient for approximately three hours (the time required to travel to University of Kentucky Hospital). I find it amazing that he never contracted COVID during this time frame. Approximately two weeks ago his girlfriend went to lunch with a coworker who was exhibiting no symptoms but tested positive for COVID the following day. Two days later my son’s girlfriend tests positive and then, one day later, my son tests positive.
I realize this is only case but, to me, a very compelling one.