Oh please, lithium "mining" might sound great, but there's a lot more to car batteries than lithium. Cobalt, which is essential for the longevity of a battery, is mostly mined by "artisinal miners" (2/3 of world's production). You know, poor people handling toxic substances to separate ores, and probably being paid less than this post cost to make. Not only that, most deposits are in geopolitically unstable regions / being explored by authoritarian regimes.

deposits in the earth != production capacity

if the increase in demand outpaces the increase in supply, you'll see a price squeeze, regardless of how much salt remains in the oceans

if someone goes and outlaws internal combustion engines, for instance, you may see demand increase quicker than supply can catch up

Clearly, but that’s a short term constraint, not a medium to long term constraint. The short term constraints on hydrogen are way worse, and hydrogen already has massive industrial demand that is being met virtually entirely by fossil hydrogen. If green hydrogen production was a slam dunk and we just needed storage, etc, then we’d already been using massive amounts of green hydrogen industrially instead of, like, 1%. (Note that in the US, 41% of electricity is clean.)