I have read dozens of studies that people claimed showed masks stop viruses, and every one of them was so flawed that no such conclusion could be drawn from it. I am left with the statement that no study has ever shown masks to prevent viral transmission in practice.

They have tried to show masks work, but they've failed. When they couldn't show it with actual evidence, they tried to lie, trick people into thinking they did, or imply masks did with related data.

As my work sometimes requires masks, I have been long aware that OSHA regulates (or did) use of masks on jobs. Masks are harmful, in several ways, and one of the worst is that they cause hypercapnia. 13kppm is ~3 times higher than the point at which medical harm starts happening from CO2 in the air you're breathing, and I don't think kids somehow get more CO2 when masked than adults. I have quit doing work that requires masking, and I will not wear a mask as a talisman, or just because someone told me to.

I was born with my face exposed to the air my forefathers breathed, and I'll die that way.