Ok let's compare the year 1000 with the year 1500. Do you believe the value of everything in the world increased in those 500 years? There was no monetary policy yet so that isn't the explanation
The explanation is the entire human race working diligently to produce, create and grow. Not because king Bobbert the 7th gave some artist some money, and not because king Jeffrey got rich by enslaving/conquering/exploring someone else.