Even if we split NaCl into its constituent parts -- sodium metal and chlorine gas -- there's not a whole lot that can be done with them.

Sodium is potentially useful towards two applications, off the top of my head. (1) Na2O is used in glassmaking, and it's possible that there are -- or that there can be discovered -- Na2O-enriched glasses that can be used in construction and as a filler substance, i.e. reduced to powder and added to cement. (2) Sodium-based zeolites can potentially be useful for carbon capture. Production of zeolites, however, also requires lots of alumina and silica.

I struggle to think of any large-scale application for all of that chlorine, though. Maybe vinyl chloride production? But the world doesn't need that much PVC...