Is it really reliable to raise children to prevent old age?
Give birth to children, raise children to prevent old age, carry on the family line, and have many children and be blessed. An old man can raise six sons, but six sons can't raise an old man. Raising children for old age is more reliable than not having a son. What is unreliable is that you just do your duty, don't expect your sons to provide for the elderly, or you have to rely on yourself.