A concentration of group "power" into any individual/s will introduce a hierarchy to the system, which begets inequality in power, which begets class systems, which begets corruption, etc.
It's why delegations and councils make sense on paper but are, even at the best of times, not perfect in practice. I understand that we may not strive for perfection in our social systems, but this does go against the distribution of power intent behind communal living in the first place. I actually like the idea of communal ownership of means of production, but I don't think it's possible to implement successfully with humans as a species (or likely any species, even ants have hierarchical importance). It might be possible with "sentient" machines at some point in the distant future, but the rest is biologically encoded in our nature.