Yes, and yes.
Some people figure out how to make do with only public transportation and a bike, but that severely limits where you can live.
Most people drive, and those who bike or use public transportation either have a car, or live in a household where they can use a car. (1-car couples, or borrow a roommate's car.)
Case in point: I took a job in San Francisco, where they told me that they were moving to Menlo Park, but a few blocks from the Caltrain station. At the time, I lived a few blocks from the Palo Alto train station. For my first month, I took the train into the city and biked to the office, which worked about 95% of the time. (I drove when it rained, or when I had to go somewhere after work.)
Later, when they moved to Menlo Park, it was a short 10-minute bikeride, so I continued to ride my bike, except when it rained, or I needed to go somewhere after work, or when I was recovering from surgery. When I met my wife, I started biking through Stanford to sleep at her place after work.
BUT: My wife and I had to move further away, and then my job moved further away, and I was no longer able to bike.
I should note that, when we were in San Francisco, we had a lot of people who were very committed to living in the city and only working where they could bike / walk / train to. We lost all of these people when we moved to Menlo Park. The only bike/train people who we kept were the company founders, who sucked it up and started driving once we could no longer fit in the offices near the train stations.