If those long-lived races had higher cultivation, they could trace things back to their origin, refine spiritual qi into primal qi or some other kind of qi, and absorb it... However, their cultivation was too low; they could not even take the first step.
In an environment brimming with spiritual qi, they could not even reach the First Realm! Their supernatural ranks had been sealed away!
Yun Shou: "How did that saying go again..."
"Why can't we take the enemy's position?"
"Reporting, because the soldiers haven't eaten breakfast!"
"Why didn't you let them eat breakfast?"
"Reporting, they can eat breakfast after taking the enemy's position!"
"Then why can't we take the enemy's position..."
It had formed a vicious cycle.
They were born with ten times the lifespan of ordinary people, as well as several times their physical fitness and strength. Even without ever cultivating, they were comparable to cultivators at the second or third layer of Qi Refinement.
After the Lower Realm where these long-lived races had originally lived was captured and merged into a mid-tier plane, they found that while they were superior to uncultivated mortals, before true cultivators they were merely playthings—playthings with an exceptionally long shelf life.
Ordinary people began to age in their thirties or forties unless they were fed spiritual medicines precious even to immortal cultivators, but these long-lived humans possessed lifespans comparable to those of Nascent Soul Realm cultivators.
If these long-lived human races wished to change their fate, then either an unparalleled great sage had to emerge and independently devise a spiritual-qi supernatural system suited to their constitutions.
Or... they had to wait several hundred thousand, even several million years, allowing generation after generation of species optimization and selection to mutate individuals capable of absorbing spiritual qi.
But that was before you arrived.