It HAS been proven that masks are useless.
The Cochrane Study, the largest study to date, the largest in existence on the efficacy of masks to stop viral transmission, was a massive study that collated 78 clinical trials, across multiple countries, with 610,872 participants.
It concluded that masks do nothing.
(In more careful scientific parlance, it concluded there is no evidence that masks have an effect on stopping viral transmission.)
Excerpts:
Regarding surgical masks:
"The pooled results of RCTs (random clinical trials) did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks. "
- No evidence they do anything whatsoever.
Regarding N95 masks:
"There were no clear differences between the use of medical/surgical masks compared with N95/P2 respirators in healthcare workers when used in routine care to reduce respiratory viral infection."
- The N95 mask does no more than the surgical mask... which is nothing.
LINK:
The Cochrane Study - Link:
It's not much fun to read, but here it is.
With all that said, if somebody still wants to wear a mask around... hey... that's fine with me.
.