If the agent has to get approval to access every account, that would be so, so time consuming, the company wouldn’t have clients/customers. There isn’t enough managers on the floor or available for that to be feasible.

Some other call centres request authorisation through the caller in the form of an OTP, which doesn’t seem like a bad system. Or some banks still require phone banking passwords (although I believe they’re mostly about protecting the bank from the liability of somebody impersonating a customer, I don’t think that is required to access files. It should be though)