What is obvious? Why they need my messages for the voice speech emulation?

The person you’re replying to is saying that in the several years the technological means to impersonate people at scale has become widely available, and because of this financial institutions are having to strengthen their security measures to defend against fraud.

When last time employee of bank or public administration in developed world paid consequences for leaking private or biometric data, copies of documents or documents themselves?

Because now you have kiddos in customer service demanding things like deed of purchase of real estate or inheritance documents.

Well, that's why we've made 'em and put 'em there - we need accountability sinks!

Wrong, I am saying that you are already an impersonation of an impersonation and that's the only reason you have access to banking in the first place.

It is obvious that what need them for is not the voice speech emulation.