So why then has there been no rebounds in Georgia? In Florida?
Perhaps, the shutdowns were not nearly as effective as your self-assumed powers of reason have assumed. In fact, there is a body of scientific opinion (maybe even some a tad more well-versed in the topic than yourself) that have argued they have had a negligible effect on the overall course of the virus.
There are lots of arguments out there.
What's the scientific reason the curve turned downward in NY? It certainly wasn't herd immunity because we're nowhere near the levels of exposure needed even there.
What mechanism do the well versed propose?