No one ever has to use a telephone dial ever again! That's the beauty of modern technology. However, to those of us who grew up in the heyday of the telephone dial, it seems an obvious thing to use; push-button phones came in when I was about twelve -- no causative relationship, I'm pretty sure -- and they seemed so much better. There was no need to wait for the slow machine to click out the number when you were dialing 889-8099, and you could play tunes by mashing down the buttons.
As I said, using a dial seemed easy and self-evident, but in an era when most people picked up the phone, waited for the operator, and then said "Hello, Central (or "Gert"), Get Me Doctor Jazz," these new-dangled dial gizmos must have baffled some people - new technology always does - and so AT&T used some of their immense profits to tell people have to use them.
It's not really a movie, just instruction, with a few still cartoons, inanimate. But it gets the job done.