You know in cities there's trains, buses, and cabs, right?
Especially in a city like NYC, essentially everything you need is within a mile. I live in Tokyo right now, and everything I need for daily life is within a quarter of a mile. I can get basically anywhere in the city in 30 minutes.
Tokyo doesn't really have a downtown, and what I described works for most of Tokyo, Osaka, Kyoto and Sapporo. I think it mostly covers all 5 boroughs of NYC.
I lived without a car in SF for 10 years and I think it covers that city as well. A lot of international cities work the same way.
Which means you have massive delays between stops, and can’t do much if you don’t have hours available.