That's silly. The only thing that cars have enabled people to do that has anything to do with prosperity is commute. And clearly, examples like Tokyo, Moscow, Shanghai, Seoul and New York demonstrate that you don't need a car to commute. All those cities have more than half of their commuters using mass transit.
So Tokyo, New York and Moscow do not function effectively?Sure there are many cars that are just “2nd use”. Or spares that could be eliminated at minimal inconvenience, but modern societies are based on communication and transportation and cannot function effectively without personal transport.
Have you ever been to any of them?
People like having their own cars. That's why they are such successful consumer products. Like TV's. It would be just as absurd to claim that TV's have "pushed human society to a new level of prosperity." That's not why we have them. We have them because we like them.
Don't believe me? Watch any commercial for a car. It shows them driving alone on empty roads, or going to a show with a glamorous girlfriend, or (for SUV's and trucks) driving along a dirt road far in the mountains. Exactly zero show people commuting. Because that's not why people want cars - they want the car that makes them rugged mountain men, or glamorous cosmopolitans, or adventurous thrillseekers. That's what sells. Their use as a commuting vehicle is a necessary evil to most people.
If we didn't have cars, our cities would look a lot different. You'd have much less urban sprawl and far more dense residential communities centered near transit. In fact, they would look a lot like, say, the areas around New York or Moscow. That would be good and bad - but would hardly be the end of prosperity as we know it.
If you want a real example, look at freight. The ability to rapidly ship freight via trucks/ships/planes absolutely has contributed a great deal to our prosperity - and things like grain, ore and ammonia shipment has a LOT more to do with that than your Amazon delivery truck.