phone communication has never been secure against evesdroppers

from the time when all you had was a party line, there has never been a time when your phone call was protected against people listening in on it (at least not unless you implemented end-to-end encryption/scrambling yourself)

the means to listen in has evolved, but it's always been the case that access to the phone companies equipment has given access to the contents of phone calls and messages.

As for the scare about how SMS is being used to protect your bank account, the security provided by such mechanisms isn't provided by the message being encrypted (at least not in any sane implementation), it's provided by the fact that it is being sent through a separate channel from the rest of the authentication (making it hard for an attacker to tap both channels), and the fact that it's a single-use code.