What is the practical value of studying the variability of human growth?

Changing the variability of the growth of people in a population can help us in practical life. For example, if, as a result of research, we find an increase in the height of people, then this will further affect the size of clothes, the size of cars and the height of ceilings. Also, a change in height will affect the determination of the norm. For example, now a man with a height below 147 cm is considered a dwarf.But if we notice that the entire human population is gradually decreasing in height and its average height is 150 cm, then a person with a height of 146 cm in such a population will no longer be considered a dwarf, since the normal range will change.