I think one telling feature is that the New York subway runs 24/7; every other metro in the world shuts down for nightly maintenance.
London can also claim a useful 24/7 service, with the night tube starting a couple months ago and the third and fourth lines (Jubilee and Northern) just opening up this week[1].
[1]: https://tfl.gov.uk/campaign/tube-improvements/what-we-are-do...
It helps that it's new and driverless.