That’s not how it works! Lithium is a fuel that gets used up by stars immediately whenever it might be produced in trace amounts. Unlike hydrogen, lithium wasn’t produced in the Big Bang. So most of the lithium that remains in the universe is produced outside of the cores of stars through the interaction of cosmic rays with other matter. Needless to say, that’s not a very common interaction (relatively speaking).

Now if you look at how larger stars operate (the CNO cycle [1]) you’ll see that it matches up with the higher relative abundance of carbon, nitrogen, and oxygen in the universe. Lithium, beryllium, and boron get “skipped over” in a sense.

Furthermore, if you look at a graph of the relative abundance of all elements, you’ll note that odd-numbered elements are less abundant than even (with the exceptions of hydrogen and beryllium). This is called the Oddo-Harkins rule [2] and it may also be playing a role.

Edit: I should also add that the third major process in stars, triple-α [3], involves the fusion of three helium-4 nuclei into one carbon-12 nucleus. This occurs in older stars that have exhausted most of their hydrogen fuel and so have built up a large core of “inert” helium. When their outward pressure from hydrogen fusion is no longer high enough to withstand gravity, they reach the much higher pressures and temperatures needed for triple-α fusion. Unfortunately for the lithium industry, there’s no chance of producing lithium this way since it is skipped over on the way to carbon.

[1] https://en.wikipedia.org/wiki/CNO_cycle

[2] https://en.wikipedia.org/wiki/Oddo%E2%80%93Harkins_rule

[3] https://en.wikipedia.org/wiki/Triple-alpha_process

There is a lot less Lithium in the universe than you might expect being element #3

There is also a lot less Lithium in the universe than our models predict:

https://en.wikipedia.org/wiki/Cosmological_lithium_problem

Helium is no 2 , and that too is pretty scarce on earth , but again helium is a very light gas and simply shoots out of the atmosphere eventually, Why is lithium rare

Lithium is not very universally abundant.

You cannot estimate abundance by atomic number like that. The big bang produced mostly hydrogen and helium, with traces of lithium and beryllium. The elements heavier than that are mostly produced by stars, and the physics of fusion have a massive impact on what elements, specifically, get made. Free protons join together to become helium-4 much more readily than any other fusion process, meaning that by the time heavier things start forming, the raw material is entirely ⁴He.

This means that things that are easily made of ⁴He are dramatically more common than anything else, making the most common isotopes after ⁴He oxygen-16 (4 alphas), carbon-12 (3 alphas, less common than oxygen because it's less stable and easily picks up another alpha), neon-20 (5 alphas), and iron-56 (14 alphas to nickel-56 which immediately decays twice through β+ to produce ⁵⁶Fe). Iron is so high up above all the other intermediate steps, because it's the last stop: In heavy enough stars, the entire core converts to iron, and reactions past that are energy-consuming, not energy-producing, so after that the star collapses.

Lithium is not on any of the major stellar nucleosynthesis pathways, which means it's only produced by exceptional processes, making it roughly as universally abundant as the other stuff that is made by exceptional processes, like scandium or gallium or zirconium. But none of that matters, because:

Lithium is abundant and easy to extract in the earth's crust.

While there's not that much of it up there, there's plenty easy to extract down here, because it's so light and likes forming light compounds, meaning that a huge proportion of all the lithium of all the rocks that came together to form the earth is reachable to us. Lithium is not rare. Any statement about lithium batteries that bemoans the scarcity of lithium is doubly confused: Firstly, because lithium is simply not scarce. Secondly, because lithium is such a tiny portion of the battery, that despite being in the name, only a small fraction of the materials cost is lithium.

Lithium price has had a few big spikes because mining is a very high-capital industry where spinning up projects is measured in years, if not decades, and we suddenly started using a lot more lithium in ~2010. Accordingly, the price has spiked from the ~$5k per ton (which is roughly in the same ballpark typical cost of extraction, where any abundant mineral prices end up at), to the heights of $37k per ton last year. Even at this high price, lithium was not even the most expensive material component in most lithium batteries, because typically only 1-3% of the battery's weight is lithium.

But these prices won't last, because having the price of a commodity so high above the cost of extraction means that new mining projects are spinning up.

Lithium is extremely abundant on earth. Unless we start launching it into space, or start building up after covering the surface with buildings and roads, we’re not going to run out.

Lithium production capacity is scarce however, since it’s a mostly useless element unless you’re building batteries out of it.

Anyway, once cities realize that they need to stop taking water from rivers, we should be able to skim quite a bit of lithium from desalination plant waste water.

I mean in that case Hydrogen fuel cells are clearly the future, just as soon as we manage to make our gravity well irrelevant.