The legal concept doesn't feel esoteric to me. In contrast, "companies" creating governments is quite rare in my mind. The historical concept you're referring to was even more of a legal concept. Those companies were individually chartered by their host governments. They might have inflicted something else on their victims, but ... Let's take the East India Company as an example. It might have appeared sovereign at times, but was trivially dissolved by the British Empire.
The legal concept doesn't feel esoteric to me. In contrast, "companies" creating governments is quite rare in my mind. The historical concept you're referring to was even more of a legal concept. Those companies were individually chartered by their host governments. They might have inflicted something else on their victims, but ... Let's take the East India Company as an example. It might have appeared sovereign at times, but was trivially dissolved by the British Empire.