The semantic understanding of the objects around you (without upload to a server).
A detailed set of actual meshes of the objects in your living and working spaces.
So much can be built on this key building block, to actually help people with their daily lives, low vision people are only one group that will see massive benefits.
I also think this technique could and should be extended generally into computer vision applications, understanding semantic meaning, volumes and masses via the often highly structured environments around us.
Starting from a principled position of meaning, volumes and meshes and then training to assign gaussian splats to those meshes seems like something clever people could solve a lot of problems with.