I get that Sam Alito doesn't spend a lot of time riding the NYC subway, but I imagine that like many of a similar cohort and socioeconomic status, it would never occur to him to, say, ride the Paris Metro or London Tube, either. And if you travel to such places and you don't ever get around that way, which also means you don't really get around by walking much, you haven't actually experienced life in those places.
Maybe it's a bit hard to explain, but exaggerating a bit, if you only ever traveled from helipad to helipad, you wouldn't really experience places either.
Not everyone has the time and money to travel, of course, but some do!
And as for the New York City subway, pre-pandemic, there were more daily rides in the subway than the population of every city in the USA other than NYC. It isn't just for the unfortunate and the mole people.
("rides" is not the same as individual riders, still it's a lot of people!)