Quality of evidence There is a moderate overall quality of evidence that face masks do not have a substantial effect on transmission of influenza.
Values and preferences Face mask use is common to prevent transmission of infections in health care settings around the world, and a widely used measure in some communities, particularly in South-East Asia.
Balance of benefits and harms There are no major adverse effects of face mask use. There might be issues with allergies in some individuals, and prolonged use of face masks can be uncomfortable or inconvenient.
Resource implications Reusable cloth face masks are not recommended. Medical face masks are generally not reusable, and an adequate supply would be essential if the use of face masks was recommended. If worn by a symptomatic case, that person might require multiple masks per day for multiple days of illness.
OVERALL RESULT OF EVIDENCE ON FACE MASKS
Ten RCTs were included in the meta-analysis, and there was no evidence that face masks are effective in reducing transmission of laboratory-confirmed influenza.
Just like the general consensus, of the scientific community, that masks don't work against the spreading of disease before 2020.
If masks don’t work against the spread of disease, why do surgeons wear masks during surgery?
I have no idea why surgeons wear masks.That is not what we are talking about. Here is straight from WHO itself from 2109. https://apps.who.int/iris/bitstream/handle/10665/329438/9789241516839-eng.pdf?ua=1
In other words, wearing a mask in a way that "might" help is being done by pretty much noone.
"If worn by a symptomatic case, that person might require multiple masks per day for multiple days of illness"