If you're implying that this means masks have no effect, you should know that correlation does not equal causation.

No, I'm implying what I said explicitly: some people have taken to deceptive tactics to try and argue mask mandates work, like truncating graphs to create apparent correlations where none really exist.

We don't know if people were actually following the mandate or not, how frequently they were taking their masks off, whether they were engaging in other behavior which would put them at risk for COVID exposure, etc

We do know this because the Delphi project has been tracking mask compliance, at least among Americans. It's extremely high, like above 90%. If mask mandates don't work with such high levels of compliance it means they don't work at all. And if masks 'worked' but had no observable effect due to other factors, that's logically the same as having no effect, isn't it?

How do you know they didn't have an impact on incidence graphs? It's entirely possible that the spikes in those charts would have been even more severe without a mask mandate

Even when controlling for increase in testing, the second wave in some places with mask mandates introduced after the first is equal in size to the first. If they worked that shouldn't be possible.

For something to be scientific you have to start with the null hypothesis. Believing in something despite evidence that it has no effect places us firmly in tiger-protecting rock territory - it's fundamentally a religious impulse rather than scientific. I could just as easily argue that the second waves would have been much smaller if we hadn't been wearing masks: I'd have no proof of that so I doubt you'd accept it, but it's no more valid than what you're arguing here. Yet maskers insist they are being scientific.

So far every piece of "evidence" for masks I've seen boils down to a correlation/causation fallacy. A few places where mask mandates were introduced as incidence was falling anyway are used to argue for them, and all the places where incidence went up or did nothing are ignored. The existence of second waves and second lockdowns despite masks is ignored. The studies pre-dating 2020 that showed masks don't seem to have any impact are ignored. The completely unstudied and hitherto-fore never proposed hypothesis that masks are meant to stop people infecting other people rather than stop people getting infected is taken as "scientific", even though it appears to have been made up on the spot for political reasons.

But don't listen to me, I'm not an expert either. Listen to the people who do this kind of thing for a living and who know what they're talking about. They know more than we do about their chosen field.

No, they don't. 2020 has made it abundantly clear that public health expertise is a massive fraud. These people systematically have no clue what they're talking about. Their predictions are always wrong, they constantly ignore evidence they're wrong, they lie all the time and their credibility is zero. As for random people on Twitter, do you really think I was making an appeal to their authority? Twitter is irrelevant, it just happened to be a place where the graphics are hosted. It's the data that matters to my argument, not who's making it.

Remember these 'experts' changed their positions on masks 180 degrees almost overnight. Now they claim they were previously lying en-masse. I don't think that's true, I think they were summarising the literature up to that point (which said masks don't really work) and then changed their views for political reasons. But even if you believe it was the other way around, it's impossible at this point to not believe in a massive coordinated conspiracy. Either they were all lying before or they were all lying now: it's not possible for it to be neither. There's really no point in making appeals to the authority of these people.

here[7] is an explanation of how masks work, specifically how they help filter and trap particles which carry COVID

I'm aware of how they are meant to work, it's obvious, nobody needs the New York Times to tell them that masks are meant to filter particles. Yet mask mandates (which is what we're talking about here) clearly don't work for any meaningful definition of work. If they did we wouldn't be seeing second waves larger than the first and being put into a wave of second lockdowns, would we?

Whether it's due to air going around the masks, most transmission being in-home, viruses being too small for masks to block them, people not wearing them right, masks being ineffective for viruses in general or whatever, doesn't actually interest me that much. That might be an interesting topic for mask manufacturers or doctors to investigate. But there's really no need to debate this: mask mandates are frequently followed by dramatic climbs in incidence, or falls, or no change at all. Meanwhile every claim that masks work is simply picking cases where the natural end of the first wave happens to roughly line up with when masks were introduced, ignoring the cases where they don't line up. Why should anyone be convinced by this?