That advice was intentionally deceptive. It was based on not having a mass run on PPE needed by healthcare workers, not medical science or safety. It also like

That advice was intentionally deceptive. It was based on not having a mass run on PPE needed by healthcare workers, not medical science or safety. It also likely led to more deaths due to the revelation that it was a lie, and people treating any further advice (which was actually medically sound) with the same kind of cynical skepticism used for liars. Rejection of masks wasn't much of a thing before this happened.