Folks got tired of masks and distancing, and started ignoring all the recommendations coming out of the medical establishment.  The virus started spreading won't stop until either we

• All get vaccinated
• Start masking and social distancing
• The virus burns its way through the population

I myself prefer number 1, as it limits the social and economic disruption caused by the virus.  I suspect we're going to see number 3, due to attitudes like the ones I see here. I wonder if I will teach face to face again during my career.

If we did #3 March 2020, this would all be behinds us and most of the population would be immune. Naturally.