It’s an historical fact: eventually all societies die out or collapse. They are conquered by another or they collapse under their own decaying weight.
Civilizations are born from struggle and undergirded by virtue. Individual responsibility and personal restraint are its foundation and have proven time and again to lead to happiness and prosperity. But prosperity is a double-edged sword for with it comes the tendency towards complacency and complacency to laziness and entitlement. These in turn lead to the rise of vice and the ever increasing need for self-gratification.
Personal restraint and virtue are mocked by the progressives who have a new vision for the world and begin to undo all those things that were the very requirements for civic prosperity.
Foundational pieces are removed or done away with one by one as gratification becomes the ultimate attainment for the new narcissistic classes. Once a sturdy foundation is removed or altered a house cannot stand, and it collapses and disintegrates under its own weight. And the next generations fail to learn the lessons of those who have failed before them and begin again with a new found zeal to repeat it all over again.
It is almost axiomatic: Virtue leads to a prosperous society, and prosperity leads to complacency, vice, and the rise of a liberal progressivism; and this progressivism leads to cultural decay and disintegration.
This cycle will continue as the very nature of man dictates that it necessarily will. Weak men create weak, decaying societies. Out of the ashes of a weak and rotting society will arise strong men. Strong men will once again create strong societies until vice is allowed to rule and the cycle will continue. Very few ever see the walls crumbling around them until they are buried in the rubble.