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.
> 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
After all these years of it not being required? I think that's... very naive with regard to how clients would respond.
I'm not saying it would be pretty, but it would still be infinitely better than what migtn happen in Bitcoin land - where people will either be able to steal money from those wallets directly, or the owners will permanently lose access.
Tldr; Bitcoin relies entirely on encryption, banking does not. So broken encryption is a catastrophe for Bitcoin, but just a bad week for banking.