It's been 18 months that I've been drivers license free.
I live in Montreal, which is a city with quite solid public transportation.
I'm also an avid bike commuter.
Long story short, using the subway, train and bike, I can get around the entire metropolitan area (I'm talking more than just the inner city core) without ever getting onto a bus. My commute times are comparable to someone travelling by car.
It's worked for me.
Then again, cars are also hugely useful to society, and I'm not about to suggest we eliminate them.