First of all, the daughters-in-law of ancient royalty or large families were mostly spoiled princesses or young ladies. They know that breastfeeding is very tiring and painful, so if someone can do it for them, who is willing to bear such hard work? So they will find a wet nurse to breastfeed and take care of the baby, so that they can end up at leisure and have a normal life and rest.
Secondly, the daughters-in-law of these large families are rather delicate and have poor physical quality, because they have been spoiled since childhood. Therefore, many people will have qi deficiency and weak milk after delivery. Without the ability to breastfeed, how can they give their babies adequate nutrition? So they can only find a wet nurse with enough milk to breastfeed them.
In addition, in ancient times, it was polygamy, and wives and concubines would try their best to compete for favor, but breastfeeding would have an irreversible impact on their bodies. If breast-feeding causes their figure to be out of shape and aging, then they will inevitably lose their favor. Without it, it will be difficult for them to survive in a big family. Therefore, in order to keep their enchanting figure and get love, they will find a wet nurse to feed their children.
This is also why in ancient times, the relatives of the emperor and the country were closely related, and the daughter-in-law of a large family looked for a wet nurse to nurse their children after giving birth. I wonder what friends think of this situation. Times have changed. Breastfeeding is now a close contact between mother and child, and a bond to deepen feelings. Even if someone is willing to do it for them, surely the treasure moms are not willing?