I've always owned a car despite having lived in Z2 etc in London.
It is completely impractical to use trains for general transport unless you plan everything months in advance or you're not paying for it. The tube and NR within the Oyster zone are an exception - those are relatively cheap and work well.
Anywhere outside of the M25 is like going back to the dark ages.
Today is Friday. Let's say I decide to visit family because I'm free, a friend cancelled plans, whatever. This is not a cherry picked example; I'm typing this before I even look.
OK, I've just checked. An advance single to my hometown is between 80 and 100 GBP depending on time. That's not including travel on either side, just mainline to mainline. There are no changes required.
Most cars will do that journey for 20 GBP, in far more comfort, at any time I would like to leave (maximum traffic variation would be approx 1 hour in a 4 hour journey).
I've bought an electric vehicle because air pollution is a real problem.
But getting rid of cars? Intercity rail needs to be fixed first, and I mean really fixed - the prices need to come down by _at least_ a factor of 2.
I haven't even mentioned the fact that if you want to live within walking distance of a station that can commute into London, you've missed the window on ever owning a home that's not an absolute shoebox; so for most that actually want a real family home, a car is still the only option because living close to the tube needs inherited wealth, a 1% job, or doing it 20 years ago.