You're assuming the centralized "neocortex" model (i.e. communism/socialism) is more effective than the distributed model (i.e. marketplace/capitalism/crowd sourced). Who knows, at this point, but the next decade will be very interesting to watch.
The problems of the centralized model is that it is in fact implemented in a distributed setting: there are breakdowns of nodes, there are broken messages, and there may be adversaries who take advantages of their positions.
China is not Communist or Socialist though. They are basically fascist, or if you want to be strict about the definition of fascism they represent an entirely new form altogether.
Doesn't communism and socialism eventually lead to fascism though? It's an inherent flaw in these ideologies. They are too optimistic and fail to account for the basic human nature that a show of weakness will immediately be capitalized on by a more aggressive party. It's a cynical take but humans have always been a kill or be killed species, and modern day capitalism has been the most successful system at controlling our worst impulses.
I don't understand your thought process. If you have a system where a corrupt organizer can end up amassing power uncontrolled, then sure you're going to end up with dictators. The system is self-selecting for a catastrophe. But this does not really say much about humanity in general.
The trick is to design systems with checks. Well-run states have these checks, both in the state organizations themselves and towards other sectors. Even if you're rich, there are limits to what you can get away with in a Western society.
And yes, these checks are not perfect, defending against corruption is really hard.
As we get better at automation, unless we screw up in the Western world, I have a hunch we're going to end up with universal income and a Star Trek-like society, probably not that far from what Marx imagined when he was ranting about the horrible conditions for factory workers at that time. The trick is to make everything so cheap that the universal income is affordable for society.
