Do you have a citation on that 5 years being achievable now (or soonish)? I am not very knowledgeable on the state of battery manufacture and from my thinking the constraints we have to work with in phones are mostly volume. In a car you can just "add more battery" as a buffer, but in a phone that space just isnt there.

TL;DR: is there research on this kind of battery lifetime without major limits when it comes to capacity?