Why are there so few Jing people in China?

Jing ancestors/kloc-drifted from Tushan and other places at the beginning of the 6th century. At that time, it was an uninhabited desert island, and they developed and built these three islands together with the Han and Zhuang people who moved here one after another. Existence is caused by historical reasons, and the number is limited by the development space. Now the division of labor between countries is very clear and relatively stable, and it is impossible to have a large number of transnational immigrants.