Smart contracts don't replace people. They replace the State.
The ultimate value of smart contracts is that they give you a powerful enforcement mechanism that isn't reliant on your local government institutions.
The parties agreeing to a smart contract can decide how the contract is split - which parts are decided by people, and which parts are code. Smart contracts can include human decision-making. "'Ask a human' is a valid step in computational law" says law prof @orgoodenough
The goal isn't to remove human decision-making entirely - the point is to remove human *enforcement*
