The Jinghu HSR (Beijing-Shanghai corridor) has made flights between those two cities unprofitable. It's cheaper, more convenient, and the door-to-door is faster than going through security and all the other bullshit associated with plane travel.
They are 1318 km (819 mi) apart. A soft sleeper ticket costs 500 CN¥ ($74 USD) and a seat is about 1/3 that price. Plane tickets are in the same price range.
Plane tickets between Chicago and Dallas, about the same distance, are over $100. This continent sucks lmao, what are we doing?