Going with your proposal for a decentralized Airbnb/Uber -- how would you handle dispute resolution and trust mediation without a centralized authority in an IRL setting, off-chain? If you have a bad actor in the system, how would you screen/remove them and conversely, how would you prevent abuse of the screening mechanism you propose? Relying on the blockchain as a decentralized database/audit record is one thing, but I think IRL enforcement and mediation of off-chain matters are critical prerequisite matters that need to be addressed before these types of marketplace businesses can even be considered feasible as dApps