Corporations don’t own themselves though, people do. Effective ownership and control are the main goals that benefit society, as long as the organisation is well run and generating useful goods and services, and employing people, we all benefit. Inheritance is an obstacle to that because it’s effectively random in terms of the competence of the inheritors, but there’s nothing random about the leadership of companies. By and large it’s based on merit. If it isn’t, then sure, corporate governance is a legitimate area for policy making.

I think you might be overestimating how much merit is a factor in the selection of board members. Corporate boards are incredibly incestuous. The most reliable way to get on a board is to be in an old money family and know other people on the board.

One could argue that the current system of selecting corporate executives produces no better result than the general election process used to select some government officials. Certainly there is no lack of poorly run companies in the modern world, especially when compared to highly competitive companies like Apple under Steve Jobs and Tesla/SpaceX under Elon Musk. The advantage to corporate boards is that candidates don't have to spend time and energy with public campaigning, but they gravitate towards conservative governance that is unable to adapt to changing times.

At any rate, the competence of the leadership at companies doesn't really matter. If they make money they can be taxed on that. How competent the leadership is may or may not impact how much money they make. Poorly managed companies may even make more money in the short term.

Well, badly run companies die and get eaten by their competitors. That’s fine. We do of course need to make sure markets are competitive and that incumbents aren’t unfairly privileged, so there is a role for regulation, but the basic competitive system is fine.