Depending on how rowdy kids are, it's not even easy in the car. You're strapped in, focused on roads, and any "incidents" they incur may require you to pull over.

The other thing about public transit heavy cities is, in order for people to use them, they have to be much more walkable - in other words, not wasting their wide open space with eight-land roads, or ocean-sized parking lots. That also means, if all you're going out for is groceries, it would be a waste of time to get in a car, or a train; just walk to a grocery store and back. Plus, if the trip genuinely does work out conveniently, you would not need to buy huge quantities in bulk each trip - just take multiple short trips through the week.

I happen to have a somewhat lucky city living situation, and this is pretty much how it works out for me. Sometimes when someone visits me, they offer to drive me to the grocery store, and it's basically just as much hassle as walking, thanks to the pedestrian underpass I normally take home.