Banking systems do not require consensus. So, it is a single party that has to make a trust decision with a counterparty that it partially trusts, but may poten

Banking systems do not require consensus. So, it is a single party that has to make a trust decision with a counterparty that it partially trusts, but may potentially be a fraudulent party masquerading as a trusted party. Crypto requires consensus amongs millions of untrusted and possibly malicious parties i.e., no trust, all cryptography. Both require cryptography to work (eg: online banking transaction vis-a-vis crypto currency transfer). But the former is well-known (Public Key Encryption and Symmetric Encryption) client and server with established trust relationships that can be cryptographically verified whereas the latter is a distributed system with untrusted nodes and has different dynamics. The other issue is about correctness. If there is an error (system or human) in the banking system, there are compensatory transactions/procedures possible. Crypto has not evolved yet to accommodate these real world issues. It is also not proven that the crypto protocols are 100% correct. Therein lies the rub. The banking system is also not 100% correct, but has procedures to address the failures (complaint system, appeals, courts etc.,) but with crypto, there is no way to address the failure cases (hacks, lost wallets, corrupted drives, 51% attacks etc.,)