If you do not have children, do you like all your brothers and sisters and all of their children?
Without an estate plan, the government decides who will receive your assets. If you have no children, the intestate plan most likely will dictate that your assets go eventually to your brothers and sisters and then will reach your nieces and nephews.
If you don’t want that plan, then you need to create your own. Not all of us like our brothers and sisters equally. Not all of our brothers and sisters need the assets and resources equally and not all of their children have created a relationship with you that would make you wish to remember them. Just because you are related does not mean that they should receive your assets.
Or, what if you’re an only child? Then the Legislature’s intestate plan may give your estate to people you’ve never heard of and never met. This is something that can be prevented with the proper planning.