[aninhumer]

>How do you deal with doing groceries ?

Home delivery. It's far more efficient to have a single van going to a bunch of houses than to have a bunch of people take individual cars to the store and back. Supermarket delivery in the UK is already cheap and convenient, I don't see why it couldn't be similarly good elsewhere.

>Also light rail [...] only connects places that are ridiculously expensive to rent

I think that's largely a symptom of housing shortages in general. Decent public transport makes a property effectively equivalent to one closer to job centres, so it becomes more expensive. Build enough housing and that becomes less of a problem.

>If it were up to me, I'd tear down public transport entirely and replace it with "uber rail cars".

I definitely see the potential of self-driving taxis for public transport, but I don't see why you want to completely replace existing efficient infrastructure. Rather I think their role in future will be to provide last-mile connectivity for efficient public transport links. That way you still get the door-to-door transport, but with a more efficient backbone network.