“Abundance” is kind of a tricky concept. 99.999%+ of earth’s resources are not yet within human’s ability to mine. Mostly either inaccessible or too sparsely concentrated or locked in compounds difficult to industrialize.

Titanium for instance is also very abundant. But it hasn’t been until relatively recently that humans were able to mine and process it at industrial scale.

depends by what measure… if it's just about how much lithium is theoretically estimated to exist in the earth crust, then one could twist together an argument for lithium to be somewhat "abundant" (even though even by that measure Sodium is, depending on the source, 1000 to 2000 times more abundant).

But if it's in terms of practicably available (mineable or otherwise practicably extractable at a sub-exorbitant price) lithium reserves, it's quite bleak actually, and we are currently forced to either rely on a small set of limited reserves, mostly concentrated in a few rather uncertain countries of origin… or to resort to extremely expensive low-yield extraction methods.

In contrast: Na (Sodium) is trivially and cheaply extractable from salt, which is readily available everywhere in much larger quantities (be it as sea water or from salt mines which are enormously more common than lithium mining) for cheap.