Why do you say that "concubines have to have a prince to take root in the harem"?

Although some popular Gong Dou dramas are ridiculous recently, they are still in line with history. The concubines and empresses in the harem are all the wives of the emperor. One person is above ten thousand people, and even the emperor can't be abolished casually. Even if the emperor dies, no matter who the new emperor is, the queen is a statue of the queen mother. Other concubines are not so lucky, and settling down in the harem depends on two things. The first is doting. The emperor's favor is the most important. As long as the emperor likes it, you can walk sideways in the harem, but how long can the emperor's favor last? Will the emperor be in favor when he is old? So the second one that is more reliable is children. As long as a son is born, the mother will rely on the child, and other people in the harem will not bully you casually. In the future, when a son becomes an emperor, he can also be a queen mother and a biological mother. In the worst case, the son was given a prince, and the old emperor could live in the palace with his son after his death. So having a prince is the most important thing.