The government never said that masks don't work, because "the government" is a thing which does not speak. The former US Surgeon General, Jerome Adams, who was appointed by the former president, claimed that masks don't work in his now famous tweet "STOP BUYING MASKS". Fauci did not say this; Fauci instead said that for several reasons "there’s no reason to be walking around with a mask" at that time. The White House Press Secretary was absent, so there was no comment from the former president's Press Secretary. Which of those voices, or lack of voices, or any other voices, would you say qualify as the statement by "the government"? Unless you're a 2-dimensional South Park "nutter" character, you should realize that "the gubbmint" does not share a single voice, if it has a voice at all.

If you're treating the government as a solitary nebulous entity, then accountability goes out the window. It's important to keep the individuals that make up the government accountable and responsible, as President Biden has with Jerome Adams, who is no longer the Surgeon General. Accountability is also why Fauci still serves as the NIAID Director of the NIH.