Had a different experience with Chinese trains.

Shanghai to Wuxi--no tickets at all. ID cards for her relatives, passports for us. For us that meant absolutely no indication of our seats, although it's possible there was something on her sister's phone. Note that the normal exit check on your tickets didn't happen in Wuxi, they simply glanced at our passports. Her sisters scanned their ID on the way out, this appeared to be the normal exit check.

The return Wuxi to Shanghai had tickets as usual. Shanghai used our passports to do the normal exit check. I'm guessing some stations have fully deployed ID-only travel and some haven't. The system worries me a bit--our tickets were purchased with photos of the info page of our passports, not by actually scanning them. That basically says there was a human in the loop transcribing the information--and I'm used to my name being mangled here.

Wuxi was strange, we went through the security check to get into the station and then a second security check to enter the section our train left from.