Think of those numbers as one kind of in extreme case argument.

Another reality is that most of the global grid scale energy usage is not transport via mobile batteries that benefits most from high energy density lithium batteries that pack maximal energy from least weight.

Battery farms don't move, they can use other battery chemistries that are cheaper in resources and weigh a lot more per energy unit than lithium while still powering cities, smelters, processing plants, etc.

As for desalination in general, yes, there will be a lot more of that in coming years, fresh potable water supplies are stretched from a global PoV.