> ...because we need to save them for health care workers, since masks require a hospital boundary to be effective
It was way more nuanced than what you are implying. At the time, it was not known that normal masks can have any effect and many pieces of evidence suggested the opposite. It was known that N95 masks were effective, but a) they were, and still are, in short supply and need to be saved for healthcare workers; and b) in a manner of speaking, they stop working beyond the hospital border. Putting an N95 mask on requires training and even many trained healthcare professionals put it on incorrectly and expose themselves to the virus.
Things changed when it was shown that normal fabric masks were effective.
It was way more nuanced than what you are implying. At the time, it was not known that normal masks can have any effect and many pieces of evidence suggested the opposite. It was known that N95 masks were effective, but a) they were, and still are, in short supply and need to be saved for healthcare workers; and b) in a manner of speaking, they stop working beyond the hospital border. Putting an N95 mask on requires training and even many trained healthcare professionals put it on incorrectly and expose themselves to the virus.
Things changed when it was shown that normal fabric masks were effective.