An interesting hypothesis in the article linked: wearing masks increases the level of immunization from coronavirus because the mask actually reduces the infection dose and, consequently, the viral load, leading to asymptomatic or mild cases.
This method is also known as variolation. Generally, variolation is the practice of deliberately infecting people with low doses of a pathogen to elicit a protective immune response. This was once a treatment for smallpox before the invention of vaccination. In this case, masks are considered like a sieve, through which the virus passes in enough quantity for the variolation effect.
For now, this is only a theory. We shall see.
Hi, I'm Rauf Aliev. 