Blockchains are the natural evolution of fault tolerant database systems into the multi-stakeholder domain. Databases that are not just architecturally fault tolerant (eg. using Paxos or Raft), but politically fault-tolerant (using BFT). Money is an obvious and natural use case for such multi-stakeholder database systems, but conceivably much other critical infrastructure is as well. Though of course, since we are talking about multi-stakeholder, uptake in commercially meaningful areas will inevitably be slower and riddled with political conflict.