Could somebody else provide the same amount of value (as your CEO) for a much lower salary? In principle at least, employees (including CEOs) shouldn't be compe

Could somebody else provide the same amount of value (as your CEO) for a much lower salary? In principle at least, employees (including CEOs) shouldn't be compensated according to the "value" they provide, but instead only paid the minimum necessary to prevent them from quitting, or at least from quitting too frequently.