> I completely agree with that, but the problem is finding a supply of people to argue with on niche subjects.

Beyond just subject-wise, finding people who argue in good faith seems to be an issue too. There are people I'm friends with almost specifically because we're able to consistently have good-faith arguments about our strongly opposing views. It doesn't seem to be a common skill, but perhaps that has something to do with my sample set or my own behaviors in arguments.