Simple: Unequal societies end up having their economy, politics, public affairs and media/literature controlled by the elite class that benefits from the system. This class not only keeps the unequal system that destroys the society through that control, but also they create the narrative and mythology for justifying and perpetuating that system through their control of literature (in earlier ages), and media (today). So, they create their own reality and they believe it. Every bad sign that shows society is going worse is reinterpreted, justified or dismissed and made fit into the narrative. They put themselves into a comfortable numbness. They immerse in their false reality. By the time the actual reality hits, its too late.

And even after that, a majority of the elite still reject the actual reality. They blame the collapse on ungrateful commoners, external forces, moral decay, and other gobbledygook instead of blaming their own exploitation. Just a look at memoirs of the aristocrats who fled the French Revolution demonstrates this vividly.