What's wrong with Beijing's planning for Beijing immigrants?

The high population density in Beijing has brought great inconvenience to daily management, food, clothing, housing and transportation.

Beijing put forward the plan of satellite city n years ago, but it ran aground for some reason. Changping, Daxing, Tongzhou, Shunyi, Miyun and Shijingshan in the planning of the satellite city are science and technology centers, economic centers, cultural centers, administrative centers and residential areas. The central departments and main offices of Beijing municipal government will be relocated according to the main functions of the planning area, which can not only alleviate the great pressure of Beijing's traffic and population management, but also promote the development of the city. In fact, it is somewhat similar to the current immigration plan.

Now immigration is probably the same consideration.