Why was there no class of officials in the empires of Charlemagne and Otgon I, as in Byzantium?

The officials came from literate townspeople, usually from merchants. During the era of Charlemagne and Otgon I, urban life in the depths of Western Europe almost ceased – there was nowhere to recruit competent officials.

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.