INT. DARKNESS We hear a faint beating heart. A moment later, we see a light slowly growing in the darkness. As the light grows, we see that it is coming from a glowing object in a person’s hand. The object is a hammer.
We see the face of the person holding the hammer. It is Thor. He looks tired and beaten.
Suddenly, we hear a voice from the darkness.
Black Panther: You are not welcome here, Thor.
Thor: I know. But I must speak with you.
Black Panther: You have nothing to say that I want to hear.
Thor: I come bearing a warning. Thanos is coming.
Black Panther: We are prepared.
Thor: He is not coming alone. He has an army.
Black Panther: So do we.
Thor: Thanos is not like any enemy you have faced before. He is ruthless and he will not stop until he has destroyed everything that you hold dear.
Black Panther: We will stop him.
Thor: I hope you can. Because if you cannot, then all is lost.
Eh, looks real enough to me. Fine tune the model with all the specialities that make up Marvel movies and you'll crank out good-enough drafts in no time.
I think that was pretty clear and that posted dialog is a perfect illustration.
You cannot generate the entire movie script coherently without significant human input and that's not going to change in the next several years. So, your initial claim that dialogue is "solved" is indeed false.
Is this the motherload of exaggeration?
Current language models cannot generate coherent dialog (and even then it's mostly bad dialog) spanning more than a minute or two. And their current capabilities in that area are definitely significantly below those of the average human writer.