Masks with close to zero efficacy according to a systematic review of 78 studies by Cochrane:
Where do you get thst from.. their original version quite clesrly states what i said. Ut people misinterprited what they said to erroneously claim they meant what you said.. so they are changing the wording to be more explicit so people like you dont try and put words in their mouth like you did.
I think common sense will lead most to realize masks are probably useful for many but not all airbornse diseases. There are reasonable ways to reason about it where masks could even cause a greater soread of some diseases, maybe, when used by the general public and used improperly (whicb lets face it is most people).
That said i think we can all agree we just dont have good studies that can show it was effective in the case of covid, but we do t have evidence it was ineffective either.