The main reason is that taking care of children is too risky, and the retirement age will definitely reach 60. Physical strength and energy can't keep up, what's more, taking care of children is not only raising children, but also giving him some guidance, cultivating some hobbies and even forming good behavior habits and healthy psychology and personality.
Children who have been with their parents for a long time are far more frustrated, expressive and psychologically healthy than those who have been with their grandparents for a long time.
In fact, not taking children is for the better development of children.
The growth of every child is not just as simple as growing up, and nothing is more important than companionship. So after I retire, I won't take care of my children, but I will try my best to help them in other ways.