We're limited to lithium?

And the immediate response is that batteries are not viable in their current state. As is hydrogen. And that response goes on to talk about how theoretical future hydrogen technology will make it viable, while ignoring the same theoretical battery technology.

With one major caveat: hydrogen is a known quantity - the energy density cannot change, it will never get better than what it is now. We're increasing battery storage density while reducing weight and other challenges constantly. Over time, I see no scenario where hydrogen beats battery. We currently have no theoretical limit to what we can achieve with batteries. We can't extract more energy out of liquid hydrogen than we do now.