I suggest that the problem is our human nature: power corrupts. It doesn't matter what the seat of that power is: government, corporations, church, banks ... it will flow to the center and seek control.
In all human history nobody has found a formula to keep power dispersed and least corrupt. Many many, from Marx to Spooner to Sun Tzu, have opined about the best framework for controlling and harnessing that power, but every time a concrete proposal is made, it hinges (whether it admits it or not) on somehow interrupting the basic human tendency to game the system for max personal advantage.
The one constant of political tectonics has been:
there will be war.
No empire holds forever.
Real war, famine, hardship has been held off on a global scale to a degree not seen for two millennia. I wonder if our eventual destabilization will outclass the emergence of what we call the dark Ages. I fear for my children.