As I understood it China was fairly restrictive on who / how many of their own people could leave China for where as a tourist.
Is that not the case anymore.
This squares ok with geopolitical reasons, but not economic ones (although they certainly influence that map now and in the future).
It's hard to know. It's extra hard to know on outgoing as what I heard a while ago from someone from China (hard to know if they were really authoritative) was even if you qualified to go someplace else from inside China... your odds of approval was somewhat random / would ebb and flow.