The physical lack of materials for significantly more EVs to...

The physical lack of materials for significantly more EVs to come into being - is not primarily lithium !

There is actually a lot of lithium in the world of course.

Economics though—esp if aim to maximise the extraction of lithium from the source material with eg. optimised processing after mining if hard rock, & to be suited for end- user battery applications, within a worthwhile price for lithium which there currently is now .
++ so much else, many factors including being overall an economic resource and resources definition, mining approvals & permit processes, ownership, & esp jurisdiction as Serbian protests illustrated this week