Anthony Fauci literally said that "there's no reason for the general public to be walking around with a mask". On television. I'll link to this version, since hilariously, facebook has "fact checked" it:
https://www.facebook.com/DeannaForCongress/videos/3682499312...
(note that I have no idea who "Deanna for Congress" is. This is the first version of the video I could find -- linked from a reuters article also claiming to "fact check" it [1] -- because google has gone out of its way to bury the video.)
It's pretty darned ironic that this is your preferred example of people "not understanding" messaging. If you search for this, you will find hundreds of other articles "fact-checking" this, even though he said it, it's not debatable, and the various walk-backs and fact-checks and whatnot simply make the issue look ridiculously farcical.
Just to underscore the point here, the Reuters "fact check" admits he said it (since, to be fair, he said it), and the only "fact checking" involved is that the official government position has changed. It wasn't taken out of context. It wasn't a misquote. It wasn't "misinterpreted". He said masks don't work other than blocking "the occasional droplet", and that there's no reason for the public to wear them. This was March 2020.
While it's true (and obvious to anyone) that the government position has changed, it doesn't change the "fact" of what was said in the past. And yet, people persist in trying to do this absurd stuff.
Let's be honest with ourselves: if this leads to doubt amongst the public, is this the fault of a dense public not understanding sophisticated, super-nuanced messaging, or simply that the messaging was muddled and has wavered over time, and that some parties are engaged in blatant attempts to re-write the factual record?
[1] https://www.reuters.com/article/uk-factcheck-fauci-outdated-...