The biggest use-case I see for hydrogen is more of an energy storage and transfer mechanism. With the world switching to renewables that generate power inconsistently, some countries are looking at putting the extra power into hydrogen generation via electrolysis, which can then be used at night/low-wind days to keep the power grid stable.

If we ever get to the point that we’ve got a surplus of renewably generated hydrogen, then it could make sense to start using to power cars, heating, cooking, whatever.