This is a very important thing for our Protestant friends to grasp. The Church is a hierarchy of hierarchies, and each local Episcopacy models the Church Catholic. Further, each local parish models, with some necessary alterations, the Episcopacy, and each house forms the Church Domestic where the man of the house is also the priest of the house.
Each time the question is raised, "why wouldn't the Pope just order X", that is the answer. The bishops are sovereign princes of their dioceses. We are held together by faith kept in common, not by command and control structures.
St. Peter spoke of "living stones built up, a spiritual house, a holy priesthood, to offer up spiritual sacrifices" for a reason.
The Pope "owns" the Bishops in that he has sole authority to hire and fire them. If that is not a command and control structure what is?