> the place hydrogen might work is airplanes where the energy density of batteries doesn't work.

How is that going to work? Cryogenic liquid hydrogen? High pressure tanks? Those don't seem practical for an airplane.

What does work for airplanes is to use carbon atoms that hydrogen atoms can attach to. Then, it becomes a liquid that can easily be stored at room temperature in lightweight tanks. Very high energy density, and energy per weight!

(I think it's called kerosene.)

Diesel, kerosene, rocket propelled RP1, and fuel oil / bunker fuel in the case of cargo ships.

It’s not a coincidence that where easy of handling, storage safety, and high energy density are needed everything seems to converge on compression ignition medium to long chain liquid hydrocarbons.