History. I keep losing my place on books with random touches, and I dislike the process of finding it again through sampling. Spoilers! The history feature fixes that.
And the built in equalizer. And the speed shifting. And the file management. It's just a great app.
One thing LLM's could do for me is a "recap" feature. I sometimes completely forget listening to books when I'm halfway through. So I'm either having to Google for synopsis per chapter or just start over. Mostly i just pick something else to listen. If it could recap up until where I'm at that'd be pretty neat.
And the built in equalizer. And the speed shifting. And the file management. It's just a great app.