After the demise of the Qing Dynasty, why didn't Manchu nobles escape to the grassland like the Yuan Dynasty, but stayed?

Compared with the Yuan Dynasty, the Northeast generation, the hometown of the Qing Dynasty, was out of its control at the end of the Qing Dynasty. At that time, there was not a large number of Han people in the northern grassland of the Yuan Dynasty, but it was different in the northeast. From the Tongzhi period of the Qing Dynasty, people from Zhili and Shandong migrated to the customs area in large numbers to avoid natural disasters or wars. The original number is far less than that of Han and Manchu, and more of them are still in the Central Plains, so there are even fewer Manchu people staying in their hometown. At this time, the northeast can only be regarded as the hometown of Manchu.

Needless to say, at that time, all forces were willing to let Manchu people return to their hometown. Even if the Manchus have gone back, it is true that the northeast is under the control of the Han people, and Japan still has foreign forces. When they go back, they will inevitably be controlled by others. It is impossible to make a comeback. The original intention is at least to have enough talents, which is exactly what Manchu people lacked at that time.