I read stories of hospital workers reusing single masks across days, and being forced to wear cloth masks. Yes, some hospitals were trying to keep a cache of PPE, but other hospitals simply had no buffer whatsoever.
That suggests they did not have sufficient masks. And I've also read article on the general lack of availability to hospitals. For instance:
Vox March 27, 2020: Why America ran out of protective masks — and what can be done about it.
As for helping stop generalized spread - without getting upwards of 50% of the population 'immune' (meaning wearing masks) you really would not be able to significantly slow viral spread. And without it getting above 20%, you would see no observable slowing in spread. I don't know anybody who claims there was sufficient PPE available for upwards of 50 million people on a daily basis, never mind 150 million.
That least bit is the key: not only wasn't there enough PPE for health care workers, in the immediate, emergent situation in March, there was nowhere near enough PPE available to the general population for it to have made any difference whatsoever to viral spread. Any claims that it would have done so run up against the availability constraint. And from a purely epidemiological perspective, you would want those most likely to come in contact with the virus to be most protected; by limiting the spread there, you limit the spread from those people outwards.
Did Fauci say the masks didn't work for the public? That they were too stupid? I don't think so. Even on March 3, he pointed out that they would be useful for infected people to wear to avoid spread, and that they would be useful, at least a little, to protect from droplets. But he also was clearly very concerned, maybe more concerned, with fomites (which, after more was known about the virus, turned out to be incorrect). Now, if one wants to make the observation that nobody, including Fauci, appreciated that the virus spread so much more effectively via droplets and aerosols as opposed to surface contact, then sure - but that is only obvious in hindsight, and I would suggest that Fauci's wording was carefully couched, always talking about "now" or "right now", and often reiterating that things could change.