No danger also means no opportunities, at least that's how Shen Lang sees it.
Previously, while passing through the Death Plains, Dark Canyon, and Heaven Breaking Domain, they encountered obstructing beasts. After slaying these beasts, they gained the corresponding Essence Qi or Divine Soul Essence.
The remnant souls of gods and demons on the Death Plains would leave behind Divine Soul Essence that could enhance the strength of the Divine Soul upon death.
The humanoid monsters in the Dark Canyon would leave behind Essence Qi that could simultaneously strengthen the Physical Body and Divine Soul upon death.
The cloud beasts in the Heaven Breaking Domain would leave behind cloud-like Essence Qi that could help one break through bottlenecks upon death.
This is the fundamental reason why Sun Wukong and others could make rapid progress in cultivation along the way.
