[Nasrudith]

And the converse - if you own the political process then why aren't you wealthy? In an ideal system the answer would be "because 1/Nth of the power isn't worth much", but there in practice are always power bottlenecks that give disproportionate sway.

Even assuming a given ruling actor is principled and incorruptible, an archetypal "good king", there would be many other aspirants who want to replace them by means fair or foul. Large piles of money just lying around have always been an attractive nuisance for thieves.