I think it's important to distinguish between limitations on power imposed after the fact, and limitations on power that prevent one from exercising their power

I think it's important to distinguish between limitations on power imposed after the fact, and limitations on power that prevent one from exercising their power. CEOs are not dictators in that they answer to a board, shareholders and, ultimately, the law. But those limits tend not to prevent CEOs from exercising their power, but are rather consequences of exercising their power. On a particular day, when CEOs say something should be done (such as firing a particular person or saying something publicly) it tends to happen. Whether or not we call a CEO a "dictator" is perhaps a distraction - although I think the word usually fits in the colloquial way people tend to use it. The important thing, I think, is the recognition that CEOs orders tend to be followed, sometimes even against the desires of people executing those orders. The controls placed on CEO's power tend to be consequences rather than immediate limitations.