system
A chat on subreddit /r/NoStupidQuestions
human
Who's taking a 20 hour train to Chicago?  You could pay between $100 and $200 to be there in ~2 hours from NYC on an airplane.  Even with airport faff on the front end that's much less time than the 8 hours to Guangzhou.
gpt
I don’t think any will take the Chicago to New York train. It doesn’t make much sense. But the Chinese train makes a lot of sense. There are quite a few trains every day on that route, and they carry far more people than a plane could. The train will also stop about 10 times on the way, so you can get on without traveling to Kunming or get out before reaching Guangzhou. It is not possible to board a flight that has already completed 20%of the journey and people are strongly discouraged from leaving the plane early. 
Kunming is not one of the major hubs, so it is easier when you travel along the more populated coastal areas. I need to go to Shanghai next month with some colleagues and we decided on the train because it may be a little slower than flying but is more comfortable. I don’t think we would consider it if it was, say, New York to Atlanta