There are lots of things that parents should do. They should talk and play with their children as babies, feed them a balanced and healthy diet, make sure they have plenty of exercise, have their inoculations, socialise them, teach them good manners, toilet train them before starting nursery/school, make sure they have a suitable education, read books to them, teach them to ride a bike and swim and a myriad of different things.
We all know that some parents fail to do some, or even all, these things. They don’t step up to their responsibilities and so we try to put into place means of mitigation, through parent education or with services direct the child.