The benefit of this political philosophy is its fractally-flexbile. If we've solved every problem and the most efficient of everything is found, then "fully-automated space communism" is the most "efficient" because everything is directed rigidly in exactly the most efficient way.

That's exactly its fatal flaw though: it's so rigid (and what you call inefficiency is called autonomy by others). People change jobs for many reasons, often because they want something better. Companies go bankrupt often because they are less effective. On a macro level, when the terrain is unknown (as it is for our reality), more autonomy means more flexibility and finding efficient solutions faster.