Excalibur Is a Cool Sword but It Doesn't Create Wealth

There is only one sword for one ruler to make one law for the whole kingdom. Why is this? For most of recorded history, this was just presumed to be the right way. Do you ever stop and ask why? There is nothing about social organization that requires this to be true. Instead of handing out swords, the lady of the lake should have become a merchant and sold stuff that people clearly needed more than a ruler, such as groceries, medicine, or cash advances.