It was a bit different.
Humans somehow managed to accomplish an impossible feat through their existence.
They were not the strongest, nor were they the fastest. They didn't have the highest potential for survival, and they didn't reproduce as fast as some other species.
When viewed objectively from the perspective of someone who believed they were above humanity, the race didn't have anything to offer.
However, that was only from a jaded and arrogant perspective.
It was exactly because humans weren't the best at anything that they were forced to innovate and find ways to survive.
Humanity had an unbelievable instinct to adapt and problem-solve. Even when dragons and other races threatened to wipe humanity out of existence, the human race always became the dominant race of any realm.
Grand Heavens Boundary was split into nine sectors. Those nine sectors had dominant races of their own and other races only appeared in smaller numbers.