"Primitive" societies were likely fairly anarchistic and monarchies probably arose from "war chiefs" with religious justifications (think divine right of kings

"Primitive" societies were likely fairly anarchistic and monarchies probably arose from "war chiefs" with religious justifications (think divine right of kings but before Christianity). Representative democracies are fairly recent. Even popular examples like Rome had very strict ideas about who was eligible to vote and even in the US women and Black people hadn't been allowed to vote for the longest time of its existence. I'm not sure what examples of "falling to extremism" you're thinking of, but to pre-empt the two most obvious ones: Weimar Germany was an extremely young republic and its fall to extremism was initiated by conservatives trying to prevent the rise of communists to avoid losing their wealth after the republic had already weakened their political power; and the Soviet Union pretty much directly followed a violent revolution to overthrow a monarchy and jumped right into military dictatorship while having to fight an enemy hellbent on depopulating most of its territory. Most of the others I can think of are successor states to Soviet republics that either were autocratic already or rapidly turned into kleptocracies after the dissolution of the Soviet Union and only adopted the dressings of democracy prior to falling apart. Also most stable monarchies aren't dictatorial. Chinese dynasties were famously bureaucratic and European monarchies had fairly intricate aristocracies that frequently got involved when it came to less clear-cut lines of succession. It's probably best to think of these as oligarchies, which as a category is probably also a good fit for many so-called democracies.