A visit may begin at JFK, Newark or LaGuardia, then lead to a Midtown meeting, a downtown dinner, a Brooklyn stay or an early train from Penn Station. Those are not interchangeable versions of “New York”; they create different first evenings and different departure mornings.
The useful question is not how many landmarks can fit into a day. It is which address has to work without stress, and how the rest of the city can sit around it with enough room to feel lived rather than crossed off.