My first reaction was to consider this as pretty damning of mass use. But when I considered it more I don't think the study is as damning of masks as it is of m

My first reaction was to consider this as pretty damning of mass use. But when I considered it more I don't think the study is as damning of masks as it is of mask mandates. The problem is only ~30% more people wore masks in the intervention arm of the study. So the best possible outcome, removing 30% from the infection group entirely (essentially taking them out of the population -- a "perfect spherical mask" approximation), is a 30% reduction in cases. Which is substantial, but no one expects masks to be that effective anyway. 11% seems a reasonable ballpark. If everyone had worn masks it would have been easier to measure the effect of just the masks. Still, it's worth considering the big picture. If mask mandates aren't enforced, they're not worth a whole lot. Especially if you have limited political capital to spend.