How are you? I'm fine, thank you, and you? Please tell me how stupid this conversation is.

How are you? I'm fine, thank you, and you?

This dialogue in the textbook is just a simulation of a scene. There is nothing wrong with the dialogue itself, so it is not stupid.

But if learners copy mechanically, they will start joking.

The following is a joke related to it:

China students have an accident on a foreign highway.

Even people and cars jumped off the cliff,

After the traffic police arrived, they shouted down:

"How are you?"

International students answer:

"I'm fine, thank you!"

Then the traffic police left and the overseas students died.

Of course, jokes are jokes, but we can see from the side how rigid China students are in learning English.

The conclusion is that it is the students who are stupid, not the dialogue itself.