Of course there would still need to be either reputation systems or arbitration systems. The reason restaurants usually don't plainly defraud you isn't the threat of litigation, because litigation would cost much more than the value of the transaction. It's because they rely on reputation and repeat business.
Decentralized or massively federated reputation and arbitration networks are possible. Clever people would need to figure out a way to set things up, but it's certainly not a technological impossibility.
Decentralized or massively federated reputation and arbitration networks are possible. Clever people would need to figure out a way to set things up, but it's certainly not a technological impossibility.