How did the emperors made shang dynasty decline? instead of being cruel to their citizens?

As far as I know, the last emperor of that period spent all the revenue to meet his own luxury demands. He ordered to construct splendid palaces, which recruited thousands of labors. He turned a deaf ear to the sincere advice. Once the subjects raised the objection opinions against his dissolute lifestyle, they will definitely got killed. All his behaviors have triggered the anger of the citizens. Without the support of the citizens, there is no doubt that the court would be overthrown.

The mandate of heaven. It stated that if the emperor was cruel to their people they had the permission to overthrow him or her.