I think it boils down to collection and processing of information. Add to that the fact that different actors in the system follow different kinds of goals. The real world is very complex and in order to transport information we need to simplify and quantify according to some model we made up. Further up instances work on the model instead of the real world. Those models become more and more abstract the further up in the chain you go. The reason for this is the limited information processing ability. One human brain can only handle so much. Talking or writing can only transport so much. An organization can only handle so much. We can have worse or better abstractions and less or more efficient organization structures and communication methods. But if your basic unit of information processing are humans with their limited brains it will always be difficult to do any central planning. Especially if the information gets distorted on the way and rules are not followed as they are intended. Then you need to add control systems that take further resources and control systems for the control systems and so on. I assume this is why central planning has failed in so many areas.

But what if we could create a super brain that can handle all the detail information collected at the lowest level and integrate it into one huge model of the state of the world? There would be no misaligned incentives inside of this brain, no communication bottleneck, no abstraction loss.

I'm sure that we won't "simply create" such a central instance and make it work in a single try. But I'm sure that it could work in some areas and produce very good results. Then it's up to our governments and society on how to use this power.