You also get to decide on who gets your assets. Children do not have a statutory right to inherit from you if you do not want. A lot of children are under the mistaken belief that their parents MUST give them an inheritance. NOT TRUE.
A parent can give their estate to whoever they want to. In most states, they must specifically state that they are disinheriting their children, but they can give their money to anyone. As people age, they start to see that their children are going to be ok. The children have developed good financial habits and might not need any more money. That is where grandchildren come in.
Instead of giving money to children, we have started to see money going to fund college for grandchildren. Children might not necessarily be happy but if they have been smart, then they probably do not need any more financial help as hard as that might be to swallow.