When was it that directors finally realized that it’s not in any conceivable universe interesting to watch someone talk on the phone?

“Hello, George Cabbot speaking.
“Why, hello, Georgia!
“What’s that, Georgia? You say it’s time for some lengthy exposition?
“Oh come now, Georgia. The story isn’t that complicated.
“I see. But Georgia, surely if we really need exposition you can deliver it yourself.
“What’s that? You say it’s better if I just repeat all your lines for you? But whatever for, Georgia?
“What do you mean we haven’t invented crosscutting yet? What about that nice Welles chap?
“Oh, you’re right, Georgia. He is awfully confusing. But surely we can do voiceover?
“Well, all right, Georgia. I’ll tell that to Francine. Goodbye.”

…

“That was Georgia. She said that ADR hasn’t been invented yet either.”