That may be true, but a modern money system could get you pretty close to that ideal, where the main difference is the friction of transactions. It's close to

That may be true, but a modern money system could get you pretty close to that ideal, where the main difference is the friction of transactions. It's close to ideal for a loaf of bread, or a bag of nails. I can hop on my bike and turn my money into either of those things in a few minutes. Turning money into a house is further from that ideal of course.