system
Given the following post, respond as if you're commenting on Reddit:
human
[Meta] Why are humans in fantasy and sci-fi usually the young and fledgling race?
gpt
Both settings assume great antiquity in their histories.  Elves and dragons and other fantasy creatures live for hundreds and thousands of years.  Only several generations of them would have passed since human civilization even began, meaning their civilizations likely spanned tens of thousands or even hundreds of thousands of years before that happened.  Compared to fantasy races, humans have only been civilized for a mere fraction as long (maybe a few thousand years) and are thus a "young" race.

In Science Fiction settings, the time span of antiquity is much vaster.  Humans as a species have only existed for about 300,00 years.  Yet in SF, ancient races can inhabit true "deep time", where civilizations could have existed millions or even billions of years before homo sapiens even existed.  Compared to truly elder races of the cosmos, humans are not merely young, but infants.