Relative scarcity. In one sense, there would be enough cars for everyone in the US to get one. Some people have no cars, some people have one car, some people have two, some people have dozens. Simply take one car from the people with two, and x-1 from the people with x, and give those cars to the people with 0. Everyone would have a car. So, cars are not scarce.
But, what are the unintended consequences if we do this? Ah! Why would anyone buy a car, if all they have to do is get one from someone who has two? Why would anyone have more than one, if they have to give it away to someone who has none? Obviously, no one is going to buy a car in this scenario. No one buys cars, and why would anyone make cars? After all, if you make cars you would be obligated to give away all of them except one, right? So, people stop making cars, except as a hobby. Pretty soon the existing cars start to break down. But there are no new cars made. Pretty soon, no one has a car.
Ah well, how about we simply create government factories…cars will be manufactured with tax money, and distributed to everyone for free. Sure, we can do that. Except experience has shown that these cars are going to be three or four times as expensive, and are going to be junk. We can get into all the reasons for this, if need be. And where does the tax money come from? You cannot generate tax money, since no one has any income. Why work at making cars when you are going to get one for free anyway? So the government car factory fails unless we use force to compell the people to work there.
So, everyone gets everything for free, so no one works, so nothing is produced, so there is nothing to get for free, and everyone dies. Now, jmullaney, you don’t want everyone to die now, do you? So you can see how your plan might be impractical absent robots who work for free without complaint, right?