A recent essay discusses the reason why the pecking order is so interesting in our own and others’ lives.
The main point of social hierarchy in humans is why it should have ever evolved in the first place. It is the social context in which the instinct of the female can operate when she wants a child. She will always generally choose upwards towards the best males available for partnership with best abilities, intelligence and genetic fitness. She will ignore the unfit and inept males, so that they will be unable to pass inferior genes onwards to children.
It is our quality control mechanism. Without our DNA would increasingly flounder in a morass of average abilities in in which a steadily growing number of harmful recessive genes and obfuscate the necessary genes for species survival.