I've been car-free since '99, but did it by bus until this past March.
My choice was purely economic and quality-of-life. I don't want to have to work hard enough or long enough to SUPPORT a car. It leaves me with more time and money to do the things I like.
Switching from bus to bike, besides it having become one of the things I like, has given me even more time since it's so much faster.