Even if we had teleporters, would future Tyler Cowens be writing that they're not as innovative as the car - and would they be correct, in that a teleporter is just a more efficient way of solving a problem that cars and airplanes had already partially solved?

I don't think so, because there are threshold effects. For example, consider the airplane vs. the car: having airplane travel available doesn't just mean your trips are shorter; it enables many trips that otherwise would not even be considered, and therefore enables many kinds of activities that otherwise would not be considered. If I can fly to a distant city in a few hours, that enables me to have relationships, both business and personal, with people in that city that I couldn't have if I had to take days to drive there. If things can be shipped across country overnight on an airplane, many more economic activities requiring "just in time" delivery become possible. And so on.