For me they are actually best for non-fiction, but it has to be books. Papers are too information dense.

I get easily distracted and lose attention while listening to an audiobook. This is usually problematic with fiction, because suddenly I don't know who this new character is or what's happening. And rewinding to the precise position where I stopped paying attention is of course much more difficult than in written text.

I found that non-fiction books work great for me, because even if you ignore a page or two it makes no difference, the author keeps repeating their point and propping it up with many arguments anyway.