Why are their intermediate periods between the Old and Middle Kingdoms as well as Middle and New Kingdom?

The intermediate periods between the Old, Middle, and New Kingdoms of ancient Egypt were characterized by political instability, social upheaval, and a breakdown of centralized authority. These eras often featured rival factions or regional leaders vying for power, leading to fragmentation and chaos. Such conditions fostered cultural and economic decline, as well as the rise of local dynasties, until a unifying ruler emerged to restore order and re-establish a centralized government, initiating the next kingdom.