Moses judged all the people, from morning to night.
His father-in-law, Jethro, disapproved.
Jethro saw that as the people stood in awe before Moses, they were elevated. All conflict fell away. All sores were healed. They found peace and all was resolved.
But what if there were no Moses? Jethro understood that for peace to endure, the people had to find justice and peace on their own.
And so Moses appointed judges from among the people, so that the people would learn to settle their own accounts.
In truth, all peace and all healing comes from Above. But to endure, it must work its way out from within.
Likutei Sichot, vol. 16, Yitro 2.
If there were no Moses then people would have to find their own way. Therein lies the problem. Moses was able to help provide and establish a standard which came from G-d. If no Moses then there is no heavenly standard so each is left to their own way no matter how wrong it is.