Fauci in March: "Right now in the United States people should not be walking around with masks" (https://www.snopes.com/fact-check/fauci-masks-no-longer-need...).
Both continued with detail about saving masks for health professionals and added more context. However, both Adams and Fauci made statements in the early pandemic clearly stated that one shouldn't be wearing masks.
masks for viral protection isn't a new topic, and plenty of research is available[0] -- unless you're talking about only viral research pertaining to covid-19, which is fairly over-specific to legislate against/towards.
in other words: it was understood in the general scientific and medical public that masks help to reduce or prevent spread of airborne virus, to claim that the government should have waited for specific research to a singular strain is both excusing a willfully in-active government and portraying that government as scientifically credible for doing the so.
These actions, given the evidence that already existed that masks provide a net benefit against viral pathogens, were scientifically unsound. If I had the complete picture that was available to the U.S. government then maybe I could justify the actions by knowing that a call to use masks would cause a profound shortage of PPE for those that needed it -- and I think that's exactly what happened: the government saw that a call to use masks would cause a lack of goods, so instead of looking entirely ignorant to the problem it was decided to latch onto the logic that covid-19 was somehow totally unlike any virus and that novel research would need to be undertaken in order to justify the need for masks.
It's my opinion that masks were already well-enough researched, and that the surrogate viruses that were used in this research prior to covid-19 were a 'good-enough' approximate to understand that masks would be a net social benefit, if available. It's my opinion that other co-factors that the government was privvy to influenced their decision to push against mask use temporarily in the beginning.
[0]: https://scholar.google.com/scholar?q=mask+efficacy+virus&hl=...
Recall the proclamations from last summer that massive street protests were either magically not going to spread COVID, or that it was somehow acceptable because "racism is a public health issue".
Looks like subsequently things went off the rails there. Wonder what happened.
At least to me, that was pretty dismissive about them. That set the tone for a very large set of people.
Edit: This was US based. I do not know what other countries were saying.
2. It still makes sense to wash hands, use gloves, and wipe down anything coming into your house that was recently touched by strangers. There's no good reason to allow a known vector, even if it's lower risk than airborne.