I used to argue with ancaps and it was not only completely unproductive but ended up taking me to a kinda dark place. I think it was the first time I really felt hatred. It's dumb because obviously there are worse people in the world but like, rationally I know serial killers are bad but I don't really feel anything when I think about them, they're a threat that need to be stopped and that's that for me.

Ancaps, otoh, got under my skin like nothing else has. Every single one of them is unbelievably dishonest. They constantly twist words around to mean things they don't, which serves the dual purposes of making communication with anyone outside of the cult virtually impossible, and of being able to make "technically correct claims." Imaging trying to dispute the claim "Hitler is great" and finding out halfway through the conversation that they're defining "Hitler" to mean "ice cream." That's hardly even an exaggeration of what talking to one of them is like. Meanwhile they explicitly reject empiricism, so it's literally impossible for there to be any factual evidence you can use to persuade them. As for theory, they simply begin with assuming their conclusion that everything any government ever does is bad, and they think that makes them principled because they don't understand what that means. And meanwhile, they'll constantly divert the conversation to unsolicited life advice that are based on their completely delusional vision of reality.

You cannot reason with these people because their beliefs are not based on reason. If you show that their beliefs are contradictory they literally won't care at all. If you're going to engage with them you're better off simply bullying them than getting caught up trying to untangle all their brainworms.