Like a virtual time capsule, this video from the old AT&T Archives demonstrated to phone customers how the "new" personal dialing system would replace the old operator:

As the company's Tech Channel points out, telephone technology has come a long way in the last few decades:

One by one, the conventions described in this film that aren't already gone may disappear imminently - for instance: with voicemail the norm, when is the last time you got a busy signal on a call?

From personal experience, I can tell you that the old rotary dial phones still work today, despite being eclipsed by more efficient technology decades ago.