I travel frequently, I've never flown, do not own a car (though I once did). I choose to walk or cycle as primary option, if not I then use the bus or train. If that doesn't get me to places, which would otherwise be to satisfy a whim, I don't go. The exception being my occasional trips back to Ireland when once or twice a year I then use the ferry.
When I was young and single, I lived in a place with good public transport. I didn't need a car.
Then I started gigging so I needed to be able to travel with a keyboard, amp, cables, mic stand and mic. Hard to do on public transport.
I then got married and had kids. It's almost impossible to get everywhere you need to be without the use of a car, plus I moved to a town with poor public transport.
I did get rid of the second car though in favour of cycling to the station to get the Train to work.
My children are now 17 and 19. In order to get to school / university / friends houses they need to use the car. Cycling to school is forbidden as the roads are too dangerous near the school. Older child doesn't cycle.
My wife and I like to travel the world with the kids when we go on holiday. It's very hard to get to places like Malaysia, Florida, Dubai, St Lucia, Mauritius, Canada etc for a two week holiday without using a plane.