(Scott Alexander had a blog post where he mentioned that the thing that got him to stop believing in history cranks was reading many different history cranks who all had very convincing but mutually exclusive theories of history. Kind of like that—if you can play with many different ways of seeing the world and noticing how they all seem convincing, then they may all become less convincing as a result.)
You might be thinking of this post about learned epistemic helplessness: https://slatestarcodex.com/2019/06/03/repost-epistemic-learned-helplessness/
Ah that’s the one, thanks! Edited the link into the post.