Lithium-ion is not one thing, and the alternatives being developed are not competing for the same job. Understanding what each optimises for explains why several will coexist.
Lithium iron phosphate
Already in mass production and taking a growing share. Lower energy density than the nickel-based chemistries, meaning less range for the same weight.
In exchange: cheaper, longer lasting, safer under abuse, and free of cobalt. For a car used mostly for short journeys, the range penalty is irrelevant and the advantages are not.
Sodium-ion
Uses sodium instead of lithium, which is abundant everywhere rather than concentrated in a few countries. Lower energy density still, better cold-weather performance, and potentially much cheaper.
Best suited to stationary storage and small vehicles where weight matters less. Entering production now.
Solid-state
The one that has been three years away for a decade. Replaces the liquid electrolyte with a solid, permitting a lithium metal anode and substantially higher energy density.
The chemistry works. Manufacturing millions of identical cells at automotive cost and reliability does not yet, and that gap has proven far harder than expected.
Why several will coexist
Because the requirements differ. A long-range vehicle needs energy density. A city car needs cheapness and longevity. Grid storage needs cost per cycle and does not care about weight at all.
Optimising for one costs you another, so a single chemistry winning everything was never likely.
How to read announcements
Distinguish laboratory results from pilot production, and pilot production from volume manufacturing with acceptable yield. The last one is the news, and it is the one that keeps not arriving.