Maybe the creatures of Infinite Soul Star don't know or can't tell, but Soul Cultivation is unique. They walk a path that no other cultivator has taken.
Choosing Soul Cultivation doesn't mean there are no other paths available in the Infinite Soul Star. People who cannot awaken their Soul Mark but still want to cultivate can always choose the path of Body Cultivation, focusing on strengthening their physique. This results in them having extremely powerful bodies. They can shatter a huge mountain with a simple punch and possess the capabilities of facing any type of elemental attack with the raw strength of the physical body alone.
Some people choose the demonic path and become demons by practicing demonic cultivation techniques. This has happened in the past.
However, no other cultivation path is as popular, admired, well-received, and sought-after as Soul Cultivation.