I was taught that each amazing break through is often in one dimension of the battery problem-set: expands-when-charged, holds-charge, charge-time, heats-when-(dis)charged, explosive/leaky, max-charge, etc, etc.

When each new technology is added into the meta-loop, it often adds 1% more overall efficiency. This is huge if you can do this ten times in ten years.

Engineering is a tough job, but it certainly sounds like a job that makes a huge difference to society.

Edit: here is an article from Ars Technics from 2021 - batteries have improved over a decade.

https://arstechnica.com/science/2021/05/eternally-five-years-away-no-batteries-are-improving-under-your-nose/

I bet that this continues to happen every year, the tortoise trying to win the tech-race.