Cars are actually a good metaphor, it works on so many levels. Modern cars have "democratized" access to long-distance travel in a sense, and most people don't need to do any heavy maintenance themselves. But the flipside is that places that have adopted it have become "car dependent" and build cities assuming access to cars.

Are we net better off than if we didn't have cars and simply built public transport with walkable cities?

Soon enough we'll have ads playing in our cars at stoplights.