I have watched that video, and IIRC, he's only against corporate governments that exist in our world. Not disagreeing with the video, but most of his arguments only work in the context of the real world, like how even the richest corporation can't afford to field the kind of army that Russia or America has or how our world will instantly sanction any corporate state that emerges for fear of a dangerous precedence. Your fictional world isn't bound by our rules; you can tweak the geopolitical condition as much as you want to make Corporate governments possible.

It's possible in Borderlands because a big war happened in the past and destroyed the central space government. That's one way you can make it works; there is no government left to regulate the megacorps, so they can expand into states in their own right.