I think is fair to say hydrogen fueled vehicles are experimental for now. High cost of hydrogen is a major limitation. But recent claim of 30% improvement is electrolysis hydrogen is interesting.
Also there are reports of natural hydrogen sources that might be as economical as natural gas–if abundant enough and when developed.
Hydrogen remains a clean energy source that can be transported–if only the cost issues can be resolved. Commercial adoption at current prices seems unlikely unless required by govt.