The code can still involve humans, if that is the escrow system you'd like to use. It just doesn't have to involve a centralized entity. For example, I can imagine an escrow system where you can have third party arbitration, by anyone who wants to participate in the system. Incentivized by the two parties involved.
People say that crypto is just re-inventing what already exists and a lot of it is doing that... I'm ok with that. What exists is not always the best solution.
I agree that is the ultimate solution. But crypto is not necessary to facilitate such an arrangement. As soon as a human can override the outcome, you've negated the point of using mathematical proofs. Because now you're trusting in the human rather than the proof. You can't have it both ways. Either the ultimate authority is math, or it is a human.
They're all consensus mechanisms. If you use any other mechanism to come to a consensus off-chain, then there's no point to using the chain for consensus. You just have an overly complicated distributed database with bad data in it.
I have funds in my wallet. I choose to send them to you. That is human consensus on top of a blockchain, which is the settlement layer.
In the case of escrow contracts. The funds are in a contract. Those funds will be released to a specific wallet only when two humans agree to their human consensus. The blockchain again, is the settlement layer.
When I bought my house, it went through an escrow process. I had to pay some human paper pusher thousands of dollars to do something that really could have just been done by computers for fractions of a cent and in a matter of minutes.
Escrow is one area that you're going to have a hard time arguing with me that isn't a perfect use case for blockchain. I don't care if it is 'overly complicated'... nothing is more overly complicated than the current process today.
People say that crypto is just re-inventing what already exists and a lot of it is doing that... I'm ok with that. What exists is not always the best solution.