Centralized power system is always changed by the power of its members. While it changes its members it is also changed by its members. This is a constant presence in all power centralization.
Openness allows the centralized power system and its members to formalize and control this power exchange. Openness makes this power relationship transparent and improves the benefits for both centralized power and its members.
Without openness, a closed centralized power system is still changed but most likely in a damaging way, which then also corrupts the effect over its members.
Centralized power systems are always changed by its members, and they have a choice to make it beneficial for all through openness, or make it damaging to all by being closed.