How is it that even a straightforward answer is met with criticism and disdain? I'm not sure why I'd even bother, but since you asked directly, here you go. The two most obvious answers are first, the mask mandate and second, more recently, the 6 foot rule, as pertains to schooling.
There was originally uncertainty over whether masks protected against COVID. The guidance was not clear. When the top cheese issued a clear mandate, the country erupted. Lies! Waffling! Communism! Nope, just new facts that caused a change in position to better reflect the science. There are lots of internet rumors out there about various nefarious reasons that motivated the decision, but coincidentally, the mask mandates started soon after the major route of transmission was identified (and other routes were shown to be much less likely). But it seems easier to scream at your computer than to accept that maybe folks were mistaken and owned it.
You may also recall that the CDC is set to recommend 3 feet rather than 6 between kids at school - to help get them back, which is as I read it one of the principle concerns of many on here. If this isn't a "quasi-gov health agency" as you put it admitting they got it wrong, well then I guess we see the world through quite differently tinted glasses.
Alright, your turn to tear apart these simple, direct answers to your questions - low hanging fruit in a ripe orchard - as science is self-correcting by nature, and examples of being wrong on the way to better understanding abound. But I'm sure that your opinion is much more informed.
And thank you for your kind comments on my training and character. I'm sure that our president also appreciates your respect. I think I liked your snarky statements in Russian better. They made me laugh. So does this, but in a despairing way...