Oh, I totally agree things would be screwed if we run out of gas now. But that's mostly because we've already built our society to be dependent on it.

Before the car, most people lived on a farm. Combined with their local community, they were more-or-less self-sufficient. Not being able to travel to the next town over would deny them access to specialized goods like medicines, but they would still have necessities like food and water. That's not the case today.