Bad actors are going to build their vertical power structures whether you like it or not. This is the challenge liberals are posing to anarchists: if you are unwilling to build your own vertical power structure then how do you stop the bad actors from building theirs and then using it as a cudgel against you?
Exile and public shaming are tools that only work against bad actors as individuals. They do not work when the bad actors team up and form a critical mass.
In the distant past, anarchism worked because everyone knew each other and bad actors had nowhere to hide to build their power structures and grow in strength. The agricultural revolution changed all this because of food storage and the potential for an outside group to attack and steal the food. People formed power structures and developed the first militaries in order to defend their granaries and this led to the growth of large cities where people no longer had the ability to know everyone.
Militaries also showed the power of hierarchies. Making decisions by consensus is slow. A military with a formal power structure has a huge advantage in combat against an unstructured tribe of warriors. This was proven again and again as the empires of the past conquered their neighbours.
But I digress. A large city where it’s impossible to know everyone is a huge problem for anarchists who want to prevent bad actors from forming a vertical power structure and taking over. There simply is no known social tool which can combat against the formation of conspiracies and elites within a large society.
I meant distant past before statehood was even a thing. That was before agriculture when all people lived in nomadic tribes. There were no neighbouring states because no one had fixed territories. Groups still fought among each other as they tracked the movement of migratory herds (mobile food supply) but there were no raids on granaries because there were no granaries yet.
The first agricultural societies had a really bad time. Their nutrition was extremely poor compared to the meat-rich diets of nomads. The nomads with their superior health and mobility had easy pickings on the crude granaries and poor defences of early farming villages. Statehood began when those villages began to work together and start their own militaries which led to specialized soldiers for the first time (as opposed to nomadic warriors who fought but also hunted and parented and everything else their tribe needed them to do).