Even that advantage for hydrogen is limited. It's quite corrosive, and leaks easily. It has to be compressed at extremely high pressures to achieve that density, making storage even harder.
I never understood why Japan thought hydrogen was a good bet. If they were really that invested in internal combustion, why not turn that hydrogen into hydrocarbons? There's even more energy loss, but at least you can use the existing distribution infrastructure, and not touch your engines.
They really look like they're leaning heavily into a sunk cost fallacy. Surely it can't be that simple.
Hydrogen is an attempt to salvage that investment.
Electricity is a more universal form of energy that can be easily generated, shipped and utilized more economically than hydrogen.
The only advantage hydrogen has at the moment is that it can be stored in a more energy dense manner than electricity.
Billions of dollars are being spent on research in a global effort to change this. Japan is about the only country willing to bet against this effort.