New York is really the only exception in the US to this - world class public transportation system both within downtown areas and out to the suburbs and beyond (Acella is what all of AmTrak should have been like).
Even here in San Francisco you need a car to get around efficiently (or use Uber which comes to a point where you might as well pay for a car), plus it's impossible to fully enjoy the natural beauty further afield without a car.
Well, I wouldn't go that far. The Acella sucks if you have to depend on it. As does Amtrak. It's expensive and crappy. Public transportation is designed for getting people from the boroughs into the city center, not the other way around. If you use public trans for leaving the city it's very difficult to get from the train station to your final destination, there's just so few options.
Even here in San Francisco you need a car to get around efficiently (or use Uber which comes to a point where you might as well pay for a car), plus it's impossible to fully enjoy the natural beauty further afield without a car.