A quote from "A History of Islamic Spain" by W. Montgomery Watt and Pierre Cachia gave me a sense of deja vu. We've been here before. Talking here about the collapse of the Umayyad Caliphate of Corboba( circa mid 11th century) one of the most civilized and developed cultures, not just at that time but in history in general.
"We know that wealth had greatly increased under 'Abd er Rahman III and it may be that the bulk of the population had become so materialistic in outlook that few were capable of the sacrifices needed for unity. This materialistic outlook of the leaders or of their suMForters, or both.was very probably one of the factors that led to the breakdown."