The goal of the government must be to take the most effective elements and use them for the good of the greatest number.
The pooch-screwer in all economic systems is the inherent and variable weakness of human nature - that is, in fact, the same condition that makes government a necessity.
Without a pure dominant culture of ethical, rational, "higher" motives, there will always be friction between individual desires, leading to power struggles about whose interests win out.
Capitalism might be a perfectly workable system if it wasn't for the fact that it does not include a mandatory element of humanity.
Socialism would be perfectly fine except that humans aren't perfect.
The sad fact is that no matter what intellectually fine system we come up with for economics or governance, there will always be the pressing necessity to include mechanisms to force compliance (I was going to add "on those who will not play properly, but that would include all of us to one degree or another).
Remember, Plato's Republic was ruled by a benevolent but all-powerful dictator, who had all of the human foibles bred out of him. It's no stretch to see the flaws in that plan - it's impossible to breed such a being! Besides, the benevolent dictator would be quickly overthrown.
What is there, then? Might as well face the endless struggle with an acceptance that strategies, adaptations, tricks, aspirations, and defeats will always be a part of our collective occupation of seeking perfection (a little segue into the theater of philosophy and religion), until the day of our disintegration back into the ether.
"Here lies Logtroll - he was overtaken by events"
“You never change things by fighting the existing reality. To change something, build a new model that makes the old model obsolete.” – R. Buckminster Fuller