Rest assured, people posting a lot in this and the "safest pace" thread have been going through numerous issues/topics several times during the last 15ish months . So really, cut us some slack . We are no idiots .
I did post this at least once before, it is one of my fav Ted talks :
Just beacuse it is a conspiracy theory does not mean it is not true .
Source: https://www.youtube.com/watch?v=zlvS-GrA00I
The "Masks do not work" is a statement/theory used to undermine/torpedoe any kind of effort to actively fight the pandemic/the virus . It is one of several, some rather complex, "ideas" that repeatedly, over and over, and interestingly ALWAYS when it would be REALLY important MORE people work together to suppress, surface . Like many other inaccurate statements re SARS-CoV-2, Pandemic, NPIs, what is really going on etcetcetc, it has it's root's in traceable sources, or at least the sources using it almost always have some very specific things in common . For instance, ignorance about immune system and it's potentially desastrous workings re. SARS-CoV-2 infection and "masks don't work" pretty often go very close together .
If nothing else helps you, just read that quote on "conspiracy theories" Robin provided above one more time .