I like practical studies. I don't really care about what computer models tell some people, or what fancy aerosol sprayers tell others about particulates getting through different materials strapped to mannequin heads in plexiglass enclosures.
Take two groups, equal in size, one group with masks and the other without masks. Put them in the same environment, and after a certain amount of time passes, tally up how many from each group got sick in the time span. Sometimes thousands of participants, sometimes over years--RCT (Random Controlled Studies). There have been either 10 or 11 such studies done to determine the efficacy of masks against the transmissibility of any respiratory viruses. The most recent one, people often call "the Danish Study" examined COVID19 specifically.
It's unanamous every time...
ACP Journals
Meta-analysis on facemask use in community settings to prevent respiratory infection transmission shows no effect
There is no difference between wearing a mask, and not wearing a mask, regarding transmission of any respiratory viruses. It is all 100% nonsense.
https://www.nejm.org/doi/full/10.1056/NEJMp2006372
Every single person on Earth had COV2 weeks, maybe days, after it transmitted to the first human. It's not whether we have it that makes us sick, it's how much we have (the viral load), and whether or not our immune systems are healthy enough to fight off propagation, and then infection by any given thing.
The false belief that masks do any good outside of woodworking shops is dangerous. It gives peoples' stupidity the confidence it needs to go out and spread (potentially dangerous) diseases to a public already weakened by their own stupidity. If a real pandemic actually ever hit, it's all the uselessly masked up government ninnies who will die first--thinking they're walking around with their magical Faucifields™ protecting them.
COMMENTARY: Masks-for-all for COVID-19 not based on sound data