Large groups of humans living together, including large human societies, develop values and rules that follow from those values that to some degree provide for the welfare, sustainability, and survivability of the group or the groups perish. As the elites in the society generally design, implement, and enforce the rules, they feel constant internal pressure to mold the rules to serve their own narrow interests and external pressure to develop rules that serve the broader interests of the entire society, i.e., utilitarian rules. This results in a a set of rules that contains some rules for the exclusive benefit of the elites and other rules for the benefit of the whole, including non-elites.
However, if the external pressure is reduced in some way, for example if the elites become more insulated because of the accumulation of wealth or other forms of power, then the balance is tilted towards the values and narrow rules that only serve their interests. This can create self-reinforcing feedback loops as these self-serving rules may accelerate the accumulation of wealth and power of the elites. This leads to the deterioration of the welfare of the non-elites, which eventually leads to general societal deterioration which even impacts the elites, regardless of the degree to which they have insulated themselves from the problems and suffering of the non-elites. Unless this societal deterioration is addressed rapidly and forcefully, the economy of the society and the society itself begin to disintegrate and develop runaway feedback loops of self-destruction, caused by ever narrowing self interest, leading to complete disintegration and collapse.
Also note that while civilization offers a great improvement in the quality of life for humans, it is at the cost of suppressing certain behavioral trends and desires that naturally occur (that would be consistent with group survival and welfare in a small hunter-gatherer group but inconsistent with group survival and welfare in a large, complex civilization). The best minds of most generations throughout the thousands of years of civilization have agreed that the benefits of civilization far outweigh the costs, but because of a confluence of several different forces many influential individuals in Western societies, particularly the United States, during the past few decades have become convinced that the benefits are not worth the costs and have successfully brought pressure to discard or reduce the civilized values, i.e., those that benefit the general welfare, from society.