Every and all established, research-based public health protocols don't suddenly turn into Opposite Day without a pretty big breakthrough heard around the world in all-caps headlines like "SCIENTIFIC BREAKTHROUGH! CLOTH STOPS VIRUSES, HEALTHY HUMANS NEED QUARANTINE!" Absolutely none of this was policy or scientific establishment prior to March 2020.

There was no sudden Renaissance of virology; they simply decided you're no longer allowed to argue with them and must play successively degrading rounds of Simon Says.