Eventually in most things, people are the core problem. Things that were working well till the time of Samuel all stopped once he had left. Even the system and establishments by God will fail to work if the people within are not ready. If the people are not ready then no institution nor policy will work properly.
When push comes to shove, it becomes possible to discern the difference in the quality of an organization. Monarchy or other similar styles of centralized government or economic systems will lead to a breakdown of the community life and widen the gap between classes to the extremes. In addition, once this kind of governing becomes the norm it is near impossible to reverse the change.
Mankind turned away from the path that was given to them by God and did not repent their evil ways. Instead looked for excuses to reject the way that was provided to them. When they did reject them, they looked to follow the ways of a king and laws of the Gentile nation.
These men rejected God’s ways. The ones in power & the elders were those in the forefront to deny such methods. Following the commandments found in 1 Samuel 8:4 was most likely too hard for these men.(The big should serve the small.) [1 Samuel 8:4]
Eventually, man abandoned the governance of God. They had wished for a system where they could easily satisfy their greed and ego.