The relationship between monarchs and their nobility was often extremely fraught, so much so that most of Asian and European history involves monarchs and nobility trying to curb the power of the other.

If enough of the nobility decided that the current monarch was not to their liking for whatever reason, they could and often did choose to back someone else, who could be a relative of the current monarch or someone else entirely. Most of ancient and medieval history in much of Europe and Asia is that happening over and over again.

China did away with its warrior aristocrat class first and replaced them with scholar officials, but that didn't prevent the eventual toppling of all subsequent dynasties when economic and political troubles inevitably occurred.