Yea the real-world on smart contracts would be legit, there would be no need to blindly trust anyone for anything. I believe that smart contracts for real-world applications exist already here is an example of how you can put arbitrage trading on a smart contract check out what they are doing to apply it to the real-world in the first of it's kind arbitrage exchange. https://bitcointalk.org/index.php?topic=3085831.0