Earlier quoted context omitted.
But again, that's not what the study measured. You're extrapolating incorrectly. First, the study conflates distancing and mask-wearing. They admit this in the paper (there is a significant increase in distancing amongst the mask wearers). There is also a large change in the size of the populations that could easily swamp the effect size (i.e. the size of the mask population was something like 9% bigger than the cont…
But, that's not what you want to measure. You want to measure whether an intervention works if people adhere to the protocol. Again, as I asked you in another comment, would you expect masks to work if people don't wear them?
No, you want to measure if an intervention works if you do everything reasonable to enact it. You don't get to invent an alternate reality where people are 100% compliant and there are chocolate rivers and gumdrop trees.
Otherwise, I have the perfect diet plan that will end all obesity, worldwide: don't eat if you're fat. Simple! If it fails, it's because you didn't follow my brilliant advice.