So long as your children have their noses wiped, and are protected, and know they are loved, they don't need their mother, specifically, to do all those things all by herself.
In the past, extended family would help care for children in parts of society, and in other parts of our society, people would be employed to do this.
This is reflected in the animal kingdom, where, for example, some meerkats look after the babies, while their parents look for food, protect the colony, and so on.
Some people are better at childcare than others. That doesn't mean that the others don't love their children, or won't do their best for them, or even that their children won't be happy and loved.
I find it very arrogant of parents to feel that they, alone, know what is best for their children, without trying to learn to be better parents, and without questioning their actions, to ensure that they are parenting in the best possible way. I think it's sloppy parenting, and not in the best interests of children.