London, Paris, Seoul, and Tokyo all shut down most of their mass transit system overnight. NYC runs it all night long (albeit with fewer trains and some diversions). By the important metric of availability that puts it among the top.
Indeed, 24-hour rail service, even though it runs at infrequent and irregular intervals, is a big point bringing NYC up to barely average in its peer group. Other measures like coverage (suburbs count), travel times, intermodal operations (awful airport connections), connectivity (think Jersey), and jitney service and taxi availability drag NYC's score down.
I can count NYC as barely average only because the peer group includes not only London, Paris, Seoul, Tokyo, and Osaka but also Rio de Janeiro, Moscow, Istanbul, Mexico City, and Buenos Aires. If I'd just used your list, NYC would be dead last in almost every category.
