Why didn't the ancient Central Plains Dynasty immigrate and graze after defeating the nomadic people?

Because there is no interest, what is the use of farmers in a cold land? Failure is enough. How can the vast grasslands be wiped out? The above two points are invincible reasons. Russia itself is a relatively great achievement of nomadic people (Eastern Slavs) after the rise of the industrial revolution. Before that, it can only be said to be a history of nomadic expansion. After the industrial revolution, Russia used its geographical advantages and professional soldiers (Cossacks, who enjoyed great privileges) to destroy the declining nomadic people armed with cold weapons and assimilate them. In the final analysis, this is the result of the development of culture and productivity.