Hydrogen is absolutely incredible for efficiency, reliability, emissions...it's great at nearly everything except energy density, which it's absolutely God awful at. Unfortunately energy density is by far the most important aspect of a practical vehicle, because nobody wants to drive around in a tanker full of literal rocket fuel just to have a range beyond a hundred miles. There's a reason the space industry has all but abandoned LH2. I can see it being an incredible alternative to battery storage at a utility scale, but not at a vehicle scale.