[Haskell-cafe] Where io-streams won't fit, comparing to conduit or pipes

Hello cafe, Now I'm preparing a presentatio for meetup for stream processing in functional programming(in Tokyo), and my part is something like "why stream processing library". While preparing material, I encountered the question that why io-streams is so simple comparing others, and the reason and downsides behind its simplicity. I'm guessing it's due to its resource handling strategy, but not so confident about it because I couldn't came up with a concrete example yet. Do you know any good example where io-streams won't fit? Let me know if you have. Thanks!