I think it’s just a matter of scale and power dynamics. You can self govern at small scale but as soon as you get too big, there’s a struggle for power which leads to a chain of events that ultimately amount to some power structure to govern those who get tired of conflict.
Discussion
At large scales, bad people are just too successful in outnumbering and using brute force to dominate good people.
They keep setting up more and more bloodshed, and whether there will be any survivors at all is dependent on whether the timeline includes sufficiently fast development of a sufficient proportion of sufficiently functional humans in the population.
For humans to finally "get good" through all this bloodshed is a long shot. Highly unlikely. But, thanks to modern technology, not completely impossible. For example, cameras and microphones and ways to store their data could potentially help shift the balance against the power of lying with guns, if that balance is ever going to shift at all.