Without an ability to cut through all the politicized and biased claims being made by purported news organizations and social media sites, it's hard to know what to believe. So I just try to go by common sense.
Common sense tells me that masks probably help a lot. Here's kind of how I envision it:

(imagine those masks actually
on the faces...I spread them out just to show how I imagine the water droplets being trapped)
Right? When we breathe out, especially when we cough, sneeze, shout, are eating/drinking, or are breathing heavily like during exercise, the air going out of our lungs includes water droplets. Some big enough to see, but most are much finer than that; some droplets can be as small as a human cell. And if we have a disease, there will be millions of virus molecules in our breath too, a few on their own, but most clinging to all those water droplets (in relative sizes, if a virus is as big as the period at the end of this sentence, most water droplets are as big across as this paragraph, or bigger).
Seems to me any mask, even Behr's crochet knit one, will stop some of those water droplets, so some of the disease. The better the mask, the finer its weave, the more droplets get captured. If it's a really good mask, like an N95, then it can stop all the water droplets and even some of the unattached virus molecules. The weave can be that fine.
No mask is perfect, though, because no fit is perfect. Some air is going to escape around the edges. But the better the fabric of the mask, and the tighter the fit, the more it will help. Something's going to get through, but less and less as the fabric and fit get better.
And a second mask is a multiplier (no, not 2 masks worn by one person, heh, that doesn't work the same way). If the first mask is getting 50%, and the second mask is getting 50% of the rest, you are together eliminating 75% of the "viral load" both people will be exposed to...so we'd say 2 masks are twice as good as one. If each mask is 90% effective, you'll eliminate 99% of the viral load, and we can say that 2 masks are TEN TIMES* as good as one.
Anyway, that's how I imagine all this stuff is happening when 2 people get close to each other. So I wear a mask, and I appreciate other folks who i run into that are also wearing masks. I'm never gonna get upset at anyone for not wearing a mask, but I appreciate when they do, because they're protecting me and them both.
* First mask gets 90%, leaving 10% out there...second mask gets 90% of that remaining 10%, which is 9% of the original total. Leaving just 1% that gets through both these theoretical masks. So together, they are 99% effective. The two masks (where just 1% gets through) are 10x as good as one mask (where 10% gets through).