Decentralized consensus & trust doesn't rely on banks and all the associated cost, complexity, obscurity, and gatekeeping that comes with them. With crypto: "Banks" can't unilaterally or fraudulently print more money, settlement is much faster & public / atomic, APIs are through transparent smart contracts rather than semi-structured SWIFT messages, and no need to rely on trust that funds are real compared to (say) Eurodollar derivatives -- i.e. many of the legacy hacks that others are talking about in this thread.