“Whatever is the source of the energy that you use to fuel the hydrolysis would be a lot more efficient to use directly for your energy needs”
That brings us back to battery-powered cars. It’s batteries versus hydrogen. I’ll stick with gasoline.
Batteries do not have the energy density to power aircraft for long distances, hydrogen does. Same for long distances with class 8 lorries. Both need the energy density of hydrogen or a hydrocarbon to function over 1000+km distances. With cheap nuclear or geothermal or wind or solar with FT synthesis and H2 electrolysis liquid fuels can be made the Navy is going that route for jet fuel underway.