Living in NYC and no longer having a car and being unable to afford one, I use it every time I leave the neighborhood I live in, mainly the subway. Most people here unsurprisingly do the same since it's so crowded, parking is either unavailable or insanely expensive and alot of NYers have never learned to drive. Also we have the only 24/7 public transit system in the country so people can and do commute or travel at all hours of the day, every day of the year (some people anyway). The system here has alot of problems: it's really old (the subway's over 100 yo), it's expensive and the service (in terms of delays, frequency of trains, let alone buses and other issues) have definitely declined. But it's still the only way to get around if you're carless unless you wanna bike or something.
But when I've spent time in other cities like Philly (where I'm from), DC, Boston, San Francisco I've had to do the same, i.e. use public transit. There are a few places in the world where it's free, which it should be everywhere. And the US is still a very car-centric culture, but that's changing w/Millennials and Gen Z's habits since many of them are moving back to the cities, can't afford cars and in many cases no longer see the point in owning one.