It doesn't, because that 88,000,000,000 is a lower bound amount of lithium on the planet not an upper bound.
If I count all the apples on the apple tree in my yard, I haven't counted all the apples on the planet. Only the applies I know about. There's probably still more apple trees out there!
That 88,000,000,000 figure also doesn't count any lithium in the oceans. Taking even a small fraction from there would make that 88,000,000,000 seem tiny.
Sibling comment is a good point. Also there are lots of other battery chemistries available that use less, or no, lithium. Or approaches burning hydrogen, or ammonia, or methane.
More broadly, this is a class of complaint that you can't see every detail of path and the destination from the very beginning of the road. The solution to that isn't to stand around and complain about it, but _start moving towards the destination_.
