At some point retail investors will get tired of losing money to scams. Crypto markets will become better connected, and arbitrage will become less profitable. But any consensus system is bound by Lamport's 2002 proof and the laws of physics: transaction latency must be at least 2 network hops *across the globe* (something like ~400 ms). Databases with limited spatial extent can run *rings* around that, and presumably it'll be profitable to do so.