In a traditional system, if there is a bug in your bank's software that makes you loose money, you can ask the bank to give you the money back. If they refuse, you can take them to court. If instead the smart contract has a bug, there's no one you can appeal to to get your money back. So I think that having humans-in-the-loop is still important, at least for big transactions.
As others pointed out, this problems are much smaller for small transaction so maybe there could be some use there. But I have to think better about this use case.