In theory, competing firms keep each other honest. In reality, the managers care more about their petty kingdoms than the health of the corporate empire. If theirs goes bankrupt, they use their skills to build a new fiefdom elsewhere.

> As corporations rival the power of nations more and more

See: British East India Company. I don't really have a relevant point to make here but corporations being more powerful than countries actually seems to be the default state that has already been dealt with somewhat, rather than a novel growing problem.

True that. There are plenty of historical companies which have absolutely dominated politics. "Standard Oil" being another example.

What's different in our time, is that it is not just one company, but a whole range of mega-companies (Particularly in technology). It has changed from a few powerful and malicious actors to a systematic problem, fueled by the dynamics of the financial markets and passive investment.