Maybe they achieved hard immunity? The spike there was much taller / narrower than elsewhere, leading to the ironic situation where the worst handling of the disease leads to great numbers once past the peak. Compare to CA where the curve was flattened and then leveled out - had we allowed exponential growth here we would also likely see fewer cases today.
Herd immunity for COVID-19 is 60-85% of the population. (The formula is 1 - 1 / R0; intuitively, the average person spreads the virus to R0 other people, so if only 1 / R0 people are still susceptible, effective R = R0 * 1 / R0 = 1 and the epidemic reaches a steady-state instead of growing.) NYC antibody tests have indicated about 20% immunity. They're still a long way away from herd immunity.
I used to look at the BLM protest videos to determine how many of them wore masks and a vast majority of them did in the videos I saw. Meanwhile those protesting the lockdowns and going to bars and beaches hardly did any.
