The Dao Bridge involved using both one's energy and soul to connect with the world. In truth, given what he currently knew about everything, it seemed like among the various power systems, these cultivators had discovered the closest path to ascension.
Dante didn't doubt that in some universe, cultivation was real. It was entirely possible to rely on external energy - maybe not always spirit energy - to methodically evolve oneself into an origin being.
In fact, the very immortals that cultivation spoke of seemed like Origin Beings. From the description and details of the highest realm of the mortal stages, which was the Ascension realm, this involved converting one's spirit energy accumulated from the start into the higher grade Immortal energy which was unmatched.