The banking sector can relatively trivially move to a new encryption scheme - this is one of the huge advantages of centralized systems. Also, the banking sector, rather than trying to provide anonymity/pseudonimity, has KYC - they can relatively simply disable remote access if they think a current system is no longer secure, and get everyone to come in to a physical office and get a secure version, after manually verifying they are the rightful holder of the account.

Tldr; Bitcoin relies entirely on encryption, banking does not. So broken encryption is a catastrophe for Bitcoin, but just a bad week for banking.