In the 6th-8th centuries the Pope did not have great wealth or military forces, but he was much more active in preaching Christianity among the barbarians than the patriarch of Constantinople. Why?
In Constantinople, the power of the emperor was stronger than the power of the patriarch. To be baptized for the leader of the barbarians meant becoming a subject of the emperor. On the contrary, no one was afraid of the pope in Europe of the 6th-8th centuries, and he strove for spiritual power over the barbarians, since secular power was not available.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.