Agreed. I think that Light and Void are two cosmologic concepts they want to explore, and have been for a while, and LF and VE are if anything more akin to props to showcase those concepts than actual “characters” to be written into the story.
The fact that people are all “they will be relevant when the plot arrives” is very telling. They aren’t really relevant or potential because of who they are as a people, they only matter for how they relate to the cosmology.