"we'll never run out of lithium" is the new "640k ought to be enough for anybody".

As we make lithium battery capacity more affordable, it gets applied more broadly, and the rate of use goes up. There is a very finite amount of any resource here on earth, and while we can get things more and more efficient, there will be a moment where we can no longer extract lithium (or other materials) required for battery production. Treating these as an endless resource is the same error we made with fossil fuels, just hopefully without as much climate change as a direct result...