Interesting. When reading dystopian SciFi books, about a future where big corporations are above state governments and dominate the world I couldn't quite believe it. But such future becomes a lot more believable now.
Not sure how that was ever unbelievable to you. Governments are and have always been relics of the past. Systems that we all tolerate because removing them would be too big a hassle for most people who are simply content enough with things the way they are—and without the people these systems continue to endure.
It has always been a matter of time before a system more all-encompassing encompassed governments as well. Naive to think otherwise.
Some companies used to have a full-blown army: "...twice the size of the British Army at certain times.[5]"
Before being nationalised of course. Nationalisation is always the end-game when a corporation becomes too powerful.