Earlier quoted context omitted.
Yes, there are always exceptions. The point is, what works works, and if you're forced to make things work, before you know it, you'll find yourself looking awfully similar to those in a similar situation. There is a reason why these business structures are so common. They work.
Is it that they're the only way that works? Or is it that everyone just assumes they're the only way? E.g. Valve took a radically different approach to management and organisational structure and seems to have been very successful.
But if you just need something that works, copying a wheel is easier than reinventing one. Better yet, just buy one.
Furthermore, understanding the reasons why the most common wheel is what it is will provide invaluable insight into making a better wheel if it comes to that. It will also tell you the market forces or anything else at play. The reasons why anything works will exist and be real, if that thing that works exists and is working already.