> Is it? Do you have empirical data to support this claim?

Yes. There’s all sorts of papers to this effect. The primary transmission vector by far is nose and mouth and masks are very well established to substantially reduce infection rates. Glasses also reduce rates but not as much. The claim that studies are frequently not replicated is a good general rule of thumb. It just don’t apply to COVID where there have been many many studies on the efficacy of masks. Not to mention many studies prior to COVID on influenza, SARS and other respiratory/airborne viruses. Sure, studies can always be better and all studies have flaws, but there’s overwhelming evidence afaik that masks are highly effective. I’ll let you do your own arxiv/pubmed research to find the studies because they’re quite easy to locate.

It’s a fair argument about whether masks at population scale / mark mandates are effective because people do fail to wear them properly and frequently. So it’s hard to estimate the true efficacy of masks in the wild, but it’s definitely well above 0 where we have fairly good A/B examples between populations that did adhere to masking and those that didn’t and corresponding COVID infection and hospitalization rates. This stuff really shouldn’t be so controversial.

> so if everyone who wears masks doesn't wear them properly, or still touches their eyes and doesn't sanitize their hands properly before eating, the effect of masks could still be minimal.

That’s not an accurate representation of the research afaik. The infection rates for contact based COVID in particular is vanishingly small. Like maybe the virus can survive on surfaces for a bit but there’s no evidence that it’s at all a meaningful infection vector. Same goes for hand sanitization. I could be wrong but my understanding is that the dominant vector by far for COVID is aerosol transmission. My uneducated hunch is that that this is also likely generally true for most other viruses like the common cold and flu - contact transmission maybe happens but nowhere near at the same rate as for direct inhalation.

> but there's a world of difference between "this seems like a good idea if you're cautious or want to reduce your changes of getting sick" and "you're a terrible person if you don't do this because this is proven to work".

I think you have displayed why you’re so resistant to the suggestion that masks are highly effective and it’s nothing to do with the science. It’s that you feel that people recommending masking have placed a value judgement on people who don’t and I totally get that. But notice I did nothing of the kind. All I’m saying is that the efficacy of masking is very well established. The value judgement piece has nothing to do with science and as anyone who tried to be super strict about it hopefully learned during the pandemic is that strict adherence is very difficult. But similarly the lasseiz faire “but mah rights” crowd swung too much in the other direction and didn’t even try. And yes, it’s also been established that communities that didn’t mask as effectively had more COVID infections and deaths because of hospital overwhelms. It’s also interesting that the anti-mask and anti vaccine crowds seem to have a lot of overlap. It’s an identity thing and science can’t resolve identity issues. Same reason fundamentalists go for the god of the gaps theory - it’s hard to admit a mistake and easier to believe that support for your position remains in the gaps that existing science research inevitably has.

If it turns out in the future that masking is ineffective and there was some massive flaw in all the studies attempting replication, I’ll gladly I admit I was wrong. But I’m the absence of any information, it’s stronger to assume that masks are effective because we know it’s a respiratory and airborne illness and it stands to reason that masks would inhibit the mechanism of action. That we do have studies around this and the majority support that properly worn masks are effective is bonus gravy. But again. Identity issues are not solvable through scientific research or we wouldn’t have flat earthers and people who believe the Bible instead of evolution.