A crucial piece of evidence IMO is "the salon story where two infected stylists failed to infect all their 140 clients (making the probability of infection for bilateral mask wearing safely below 1% for a salon-style exposure)"
There's another good point about "evidence". Do you need a scientific study in order to convince yourself to lock your door at night? Does the lack of scientific evidence in that regard make you go "I think I should not lock my door" or worse "people who lock their doors at night are crazy"? It's an absurd thing.