Bean pole families

In my family, there are kids and fewer ancestors. We tend to have a pyramid-shaped family structure, unlike the Bean Pole Families.
Bean Pole Family structure is largely recognized as one of the biggest concerns specifically for Western societies given the fact that there is a considerable number of families in which the young generation either never gets married, or the marriages are unsuccessful. One way or the other, the consequence is that the young generation tends to have very little children and in some cases, no children at all. In this way, the existence of these families in the future is susceptible. Moreover, the growing number of immigrants specifically from the East into the UK and the USA adds to the danger as Eastern families tend to produce more babies. If the trend goes on, it will not take long for Eastern families to be a majority in the Western countries. This would not be very favorable for the original nationals.