It can be explained if you cost things in hours rather than money. As we improve technology fewer and fewer hours are required to create an item. But a violin

It can be explained if you cost things in hours rather than money. As we improve technology fewer and fewer hours are required to create an item. But a violin concerto takes the same amount of human time. Which then leads to the conclusion that we really exchange time when trading. Each of us only has a finite amount of time after all.