I can articulate many viewpoints extremely clearly which I don't happen to hold, which means if I am in a debating mood I can much more precisely debate someone, rather than simply dismissing them.
I repeatedly realize my own opinions are sometimes based on unexamined assumptions, which no matter how many times I realize it and try to root it out, keeps coming to my attention over and over.
I repeatedly am reminded that almost everyone believes they are acting morally, and it is humbling to try to understand the morals of the person who seems so "immoral."
I often am floored when I realize just how different my lived experience is from the person who has formed such a puzzling belief, and it massively broadens my perspective to learn about those narratives.
These are just a few things off the top of my head, I bet I could think of many more.
Honest question -- exactly what do you get out of talking and listening to people explain 'ethically flawed' or 'counterfactual' beliefs to you? What have you learned? How better to deal with people of that sort? I realize this sounds sarcastic, but whenever I've been in that situation I've only come to the sinking realization that the discussion I am trying to have with this person is fruitless at best and damaging to us both at worst.