Given two parents, there are four grandparents. Sharing the load across six people is much better than sharing between two.
Those four grandparents could end up with anywhere from 1-8+ grandkids though, depending on how many children they had, and how many grandchildren come along
Those four grandparents could end up with anywhere from 1-8+ grandkids though, depending on how many children they had, and how many grandchildren come along