It's not like longer-term thinking and more diverse investment is going to discover us an element that's lighter than lithium and solid at room temperature and pressure, so anything that beats lithium-based chemistries at power to weight ratio, which is the most important factor for most applications, is going to come completely out of left field and likely not really be a chemical battery at all. Thinking ten years ahead won't get us a phone-sized fusion reactor in ten years, and anything less sci-fi that might power a phone or a car and not be a downgrade over what's available right now is going to be a tweak to existing lithium-based batteries. There are lots of tweaks to lithium-based batteries in the works, and lots that are now available in commercial products after huge amounts of money have been sunk into research. We're already using the theoretically optimal material, so the only ways left to improve it are tweaks, and those tweaks are happening.

It's not that you're wrong in general, you just picked on one of the few industries where it's not particularly applicable.