Why do all ethnic minorities use Han names?

The emperor gave the surname first, and then the emperor gave it; Second, ethnic minority regimes carried out sinicization reform, such as Emperor Xiaowen and Xianbei nobles in the Northern Wei Dynasty all changed to Chinese surnames; Third, the ethnic minority regime is about to perish, and in order to prevent the Han people from retaliating, they changed their Chinese surnames, such as some Manchu people changed their Chinese surnames in the late Qing Dynasty; The fourth is the current ethnic policy. One of the husband and wife is a minority, and the ethnic composition of the children can follow the father or the mother. Because there are many preferential policies for ethnic minorities, in real life, more than 99% of children are with the parents of ethnic minorities, so they are also Han names.