Why on earth would democracy (or any other form of shared power) be a rational choice for you, from an economic standpoint, if you already are wealthy enough to neuter it to the point where nearly all profits and decision-making authority are allocated to you?

Dictatorship is the ultimate in rational decision-making for a rational self-interested actor. Philanthropy and benevolence are not rational for the wealthy and powerful.

Income inequality and regulatory capture are features of the free market, not bugs. They are baked in by design.

Most countries in the world "patch" those bugs by regulation that moves them away from being pure "free market" economies. Antitrust regulation is a well-known example of this.