Here is some more data from New York. This is NY state, not just NYC.

On the left are the daily death stats. On the right are the daily new cases, i.e., positive tests.

https://www.worldometers.info/coronavirus/usa/new-york/

What does this tell you?

Tells me a lot.

1st, the perfect Gompertz curve of daily deaths, a lagging indicator of infections, tells me the infection was widespread in NYC (where most of the NY deaths occurred) BEFORE the masks, distancing and lockdowns took place.

It was a classic case of shutting the barn door AFTER the horse was out.

2nd, NYC has probably achieved herd immunity. The current reduced daily death rate in the face of vastly more pos tests tells me there are certain pockets that were spared before but are now seeing deaths.

3rd, the increased positive tests are a function of 2 things. Vastly more people being tested, and due to testing machines running PCR at 40 amplifications, many immune people are turning up positive.

4th, vastly fewer deaths in the face of a humongous surge in positive tests tells me a few things. As per above, many immune people testing pos. Doctors have developed more expertise in treating the disease. And the virus has attenuated. Probably a combo of all 3.

Viruses, like all living things (whether or not viruses are living is another debate) follow the laws of natural selection. Those that have mutations allowing them to live longer & reproduce more, i.e., infect more people. If a virus is virulent...

... as were those in the 1st wave, they end up killing their host and themselves. Those undergoing mutation to less virulent forms tend to kill their hosts less often and thus reproduce more than the virulent ones do.

Over time the virus would be expected to decrease in virulence and cause fewer deaths than those in the 1st wave. This phenomenon is called viral attenuation. I believe that explains the discrepancy in the death rates between now and in the Spring. Basic evolutionary biology