Some probate litigation originates with claims that the Personal Representative has mismanaged the probate estate.
They may have misappropriated funds or engage in self-dealing. Or perhaps the Personal Representative has mismanaged real property or stocks, allowing them to lose their value.
Perhaps the personal representative has decided to live rent-free in property belonging to the decedent, where their duty is to sell the property and divide it between the heirs.
Perhaps the personal representative is simply doing nothing, and allowing estate assets to languish. An adversary proceeding can be filed to remove the personal representative; The personal representative can be made to put money back that has been wrongfully taken; The personal representative can have his any losses charged against his or her share of the estate.