Lithium is one of the most abundant solids in the universe. The earth has plenty, it's just going to become more and more economically feasible to extract it. You can even get reasonably large amounts from seawater if you have cheap energy.
These are not "wild speculations", they are all widely know facts. It is more common in the earth's crust than lead, tin, uranium, etc which we mine magnitudes more per year [1], and there are significantly more reserves in seawater [2], where extraction is mostly limited by how much energy we need to use to extract it.
Do you know how many billions of dollars worth of platinum group elements (platinum; Pt, palladium; Pd and rhodium; Rh) are literally lying on the roads and roadsides of G20 countries?
As dust from in use catalytic converters it's substantial. And unrecovered.
There's a problem with economic feasibilty - extraction costs (digging up and processing every road surface and road side) are prohibitive - greater than the value of the material.
From your [2]
The advance is still not likely cheap enough to compete with mining lithium on land,
In a nutshell this is still very much the issue with mining seawater for Lithium, Uranium, etc.
The 0.2 parts per million (PPM) is a problem, a literal ceiling on diminishing returns, the more you extract the less remains and it's tricky to keep processed seawater from mixing back with unprocessed.
Per [1], lithium is somewhere between "too rare to consider" and 33rd in the list of elements sorted by abundance. The yield of the other quoted elements from their respective ores are magnitudes higher than that of lithium, and those ores are also important sources of other metals such as silver as byproducts of the refining process, so there is relatively much more value in exploration and mining those elements vs lithium.
Your claims of economic feasibility are still well within the range of speculation, you haven't backed up your claims with any serious evidence or analysis. Your claims of abundance are of the flavor of "wait and see how much more we find" which is speculation by definition.
It's difficult to move a family and groceries around on an ebike, as it is to transit multiple people (many underaged), move the elderly, disabled, obese, or pretty much anyone who doesn't fit into the image you appear to have of people transiting.
From India to the Philippines and out to Indonesia rides a population on petrol engine scooters and motorcycles that exceeds the US population ans is currently transitioning to EV bikes.
Many are elderly, disabled, ride with multiple passengers, few are obese to US standards.
I have, and in both of those countries it is difficult and dangerous. Safety standards are extremely different, speeds are slower - traffic conditions and quality life is so uncomparable to the US that I'm finding it difficult to believe that if you've been to those countries you're not intentionally cherry picking here.
[1] https://electrek.co/2016/11/01/breakdown-raw-materials-tesla...