Hydrogen is very difficult to store even as a compressed gas, and impossible over extended periods, because it can pass right through steel walls. And it’s so light that it requires a larger volume to store any significant amount as compared to gasoline or LNG. It’s not practical. Elon is using methane to power his Starship, which makes a lot more sense than hydrogen.
The clam that hydrogen can pass through steel walls got my curiosity up. Turns out that’s not exactly true: It passes into but not through the walls. But that process, steel embrittlement, is a pretty funky phenomenon.