There’s plenty of articles to be found that say whatever you want. Broadly, you’ll find articles that state that models or theories suggest that wearing masks will probably work great and articles that say that in practice it turns out cloth masks are at most of very limited value, because you can’t say what they filter and they never fit well.
> The available evidence suggests that near-universal adoption of nonmedical masks when out in public, […] could successfully reduce R to below 1
The very clear fact that no country actually succeeded in doing this, even the countries like Japan where mask wearing is as normal as it gets, should be a hint.
What I do know is most of the time it's very, very easy to wear a mask. So maybe, if you have good reason to believe it helps, just do the easy thing even if you can't know for sure.
Plus the old story about how Schrödinger’s Japan that is the big example of masks working, also isn’t the example when it turns out they don’t work. Of course.
> Our review of the literature offers evidence in favor of widespread mask use as source control to reduce community transmission: Nonmedical masks use materials that obstruct particles of the necessary size; people are most infectious in the initial period postinfection, where it is common to have few or no symptoms (45, 46, 141); nonmedical masks have been effective in reducing transmission of respiratory viruses; and places and time periods where mask usage is required or widespread have shown substantially lower community transmission.
> The available evidence suggests that near-universal adoption of nonmedical masks when out in public, in combination with complementary public health measures, could successfully reduce Re
to below 1, thereby reducing community spread if such measures are sustained. Economic analysis suggests that mask wearing mandates could add 1 trillion dollars to the US GDP (32, 34).
> Models suggest that public mask wearing is most effective at reducing spread of the virus when compliance is high (39).
1. https://www.pnas.org/content/118/4/e2014564118