There’s possible a lot of nuance there, that his short comment lacks (and probably leading to downvotes). There were several pre-pandemic studies that suggested masks would be harmful or didn’t show an effect. Then, state-by-state comparisons of laws in the US also show very little correlation. So if the emphasis was on (still) lacking retrospective evidence, that seems a fair complaint. Very recently, there’s a preprint article by a research group that looked back at the existing studies, and showed that many of them were too underpowered to be even capable of demonstrating the expected benefits. It has a great graph of this (https://www.reddit.com/r/COVID19/comments/pxet7q/unmasking_t...)

So—in contrast to the vaccine, where the data was gathered before giving authorization was given last year—it seems that mask mandates may have been just hopeful trials that assumed there wasn’t long-term problems associated with masks, well in advance of actually having relevant data. And, in further comparison, we also have drugs like HCQ, which were pushed ahead of the data—and continue to be advocate despite continued lack of evidence in large trials. So it feels unclear that data ever mattered as much as being seen doing something? I’m saddened by it all.