As for the face mask fiasco.
If the CDC and US Gov't just provided truthful info to begin with, many more Americans would have been wearing masks nearly a month earlier, which would have reduced transmission chains. Folks could have been advised not to buy surgical masks needed for health care workers. Companies could have gotten a much earlier jump on producing cloth masks (that's what I used in Shanghai, though mine came with good insertable filters to block out small particles).
More folks would have been using scarves in the colder March weather, or other improvised masks. My doctor friends here have said all along that the public doesn't need great masks, just adequate masks since their encounters are low-risk. Though you can understand folks wanting the best protection they could get.
My parents looked around and found they had a few N95 masks that my father keeps for home repair work such as sawing or other dusty generating work. They could/would have dug those out and started wearing them in public 3 weeks earlier if the guidance has been honest.
Of course having a mask provides some protection form breathing in airborne viral particles. And all along, I've been saying the biggest benefit of masks is keeping your own germs out of the public air. Two layers of mask protection (yours plus others), and everyone who is infected wearing a mask is obviously a useful prophylactic step. I'm still reading articles that mentions staying home, staying 6 feet away and washing hands, without mentioning masks. I'd rank masks as 2nd most important, but there doesn't need to be any ranking. you combine all of the precautionary steps and the protection level increases greatly. it's pretty simple.
And btw, the 6-foot rule is pretty arbitrary. Not like the virus comes with a pair of yardsticks. And even then airborne particles can linger and float. There's an animation model of a grocery store cough that is a worrisome. I'll look for the link. Not sure how accurate, but the idea that someone can cough, walk away and you cna walk into their viral cloud a little after is unnerving. masks of course would help with that.