There are all sorts of confusing issues with lithium. It’s called a “rare earth mineral” which has nothing to do with it being rare. What’s rare is that it is rarely found in large, easy to extract deposits.

People get mislead by the terms ‘resources’ and ‘reserves’. Let me copy something over from Wiki…

“Mineral occurrences or prospects of geological interest but not necessarily of economic interest

Mineral resources that are potentially valuable, and for which reasonable prospects exist for eventual economic extraction.

Mineral reserves or Ore reserves that are valuable and legally and economically and technically feasible to extract”

Of course a new use of a mineral might mean a newer, higher value and that could move numbers from occurrences to resources. Those terms are fluid, based on demand.