Even if you got rid of all the bureaucracy bullshit and started building trains everywhere tomorrow that would not remove the need for people to have cars. And the idea that you should be able to build a building that does not have enough spaces for everyone that lives there to have one is unreasonable.
Even if I could literally walk outside and immediately outside of my door get onto a train there are still going to be times I would need a vehicle. Even if I only use it once a year I would still like to be able to own my own. I would like to live somewhere that I only need to use my vehicle a couple times a year but I still need to have somewhere to put it