They reduce the chance of bacteria entering a sterile field. They do fuck all for viruses which pass straight through because they are smaller. That bacteria that can't get through the mask circulates beneath the mask and you breathe it back in, which ends up in your lungs and you end up with bacterial pneumonia.

Fuck off with your bullshit.

they reduce viral emission.

The only way to reduce viral emission is to reduce how much you breathe every breathe you take. That's what the masks do. That means there's more viruses/bacteria not being ejected by your body which increases the chances of you getting sick. People then get sick and go get tested (or get tested because they need a negative test for some reason) and because the testing is so screwed up, you are positive for a coronavirus, but not necessarily the China virus. You're now a case and the government has authority to expand tyranny over everybody else.

You would wear that without a law for enforcement. If not, you would suffer the consequences. But you like the control aspect.

Masks do nothing. It's an airborne virus. It's all theater. It's about control. This is a classic case of a "good reason" vs. the "real reason."