Population density, mass transit, taxis.
What about Chicago, Los Angeles, Atlanta, San Francisco, Houston, Boston, Philadelphia, Phoenix, San Jose...?
California has three of the 10 largest cities in the United States and the whole state of California has slightly more than 28,000 cases, a little over 10% of the total cases in New York. You also have to consider that California receives most of the direct flights from China. I just checked, New York gets no direct flights from China.
Lastly, New York has three times as many cases (226,198) as the next city on Worldometer’s list, New Jersey (75,317).
These numbers really don’t make sense.