To be clear I (the original poster in this thread) have lived without a car in the bay area for almost a decade, and I don't Uber anywhere.
NYC is definitely more walkable--and just as expensive. Boston is about as walkable, I think (I haven't spent much time there)--and also pretty expensive!
Boston is definitely walkable. My wife and I shared a car when living there, and I'd literally go weeks without actually getting in the car (she worked in a suburb, so she needed it for daily driving). Everything was generally within 1/2 mile, including school for the kiddo, sports fields, parks, grocery, hardware, etc. Transit was also convenient and plentiful.
NYC is definitely more walkable--and just as expensive. Boston is about as walkable, I think (I haven't spent much time there)--and also pretty expensive!