The people who have been wearing masks in Asia for decades are those who have respiratory symptoms. So they are wearing a mask to prevent spreading infection not to prevent getting infection. We have travelled extensively in Asia and I can't remember a time when a majority wore masks even travelling in Thailand and Japan during the height of the swine flu.
Another argument that I have seen on here is that surgeons wear masks when operating. Once again that is to prevent them passing an infection to the patient not to protect them from disease.
As you seem to be travelling in the US I guess you are aware that the airlines are lobbying for the dropping of the mask mandate.
The CEOs argue that the increase in vaccinations and the lifting of restrictions in other countries should make the Biden administration reconsider the policy for travelers.
www.npr.org