...are exceeded by the costs.
The ruled will always despise their rulers as incompetent, every failure laid at their feet. Every iota of power granted to their ruler comes with expectations which will never - can never - be met.
The rulers will always despise the ruled, seeing them as miscreants aiming to thwart their own grand plans, throwing wrenches into schemes which, if only permitted to succeed, would do so on the grandest scale. They never have enough power to truly do the good they seek, and so always seek more.
Democracy in the end despises itself, an institution continually expanding its power but never delivering on the promises it makes to itself.