you need a decent geographic barrier like mountains or malaria-infested jungle to avoid being overrun by changoid rice goblin slumdogs that want to kill any non-domesticated animal larger than a rat in their quest for dick pills

>>18661876
But the Yue people were literally the original rice farmers (the staple crop of northern China was millet)

>>18661931
This anon knows his shit.
These guys are the OG "rice goblins".

They also lived fairly plentifully in inaccessible hills and plenty of places were known as death valleys due to malaria.
Canton and Hanoi are two separate Chinese metropoli with wilderness inbetween because that area was a deathtrap with abysmal survival rates for travelers due to disease.
The only reasonable ways to get between them were via the sea and going all the way around with Canton being linked to civilisation through paths to the east and Hanoi to the north.

>>18661869
Their killer was horsefuckers and gold.
Horsefuckers were the reason Chinese went south. They hated it there. Shit food, shit barbarians, shit weather. But the endless mountains and rivers made sure to keep guys who stick their dicks in mares a reasonable distance away.
So the Chinese took over the lowlands but were perfectly fine with Yue living in the mountains. There was fuck-all for them there...
...until they found out those mountains have fucktons upon fucktons of minerals. And that broke the social contract between Chinese cities down below and mountain chieftains.
This triggers a big migration that pushes Yue into where you'll find most of them today... Thailand and Laos. They just got Bollywooded by the locals they replaced.
Others remained in the mountains but it's really tiny communities with no real cultural drive by now. Just open air museums for Chinese intranational tourism and the occasional kidnappers looking for brides or slaves.

They never invented anything of note and got taken over by civilized people