Why? So you can independently travel to places at your own conveneince where public transport is inaccessible or too expensive.
What if you live in an inner city? So you can leave the inner city when you need or want to travel to other places at your own conveneince where public transport is inaccessible or too expensive.
What if you have a disabilty that prevents you from driving? Then you won't be able to drive and will have to rely on others or public transport. But there is a reason that lots of people with disabilities learn to drive in order to be independent and not have to rely on poor public transport.
What if you have alcohol or drug problems? Then your ability to drive is not your problem.
What if you are concerned about the environment? Being able to drive does mena you are compelled to drive. Save driving for when you need or want to travel to other places at your own convenience where public transport is inaccessible or too expensive.
What if you have passed your test but just don't feel like you are naturally a safe driver? Then you have learned to drive.
All of these are silly arguments. Driving is a useful basic life skill for an adult to have in British society. There are others. Being able to swim. Being able to read. Being able to cook. None of them are absolutely compulsory to be able to live your life, but all of them are valuable life skills.