Hydrogen fuel cells are essentially just a really complicated battery. The technology undoubtedly has uses, but powering automobiles seems a poor choice. 30 years ago, it probably seemed more reasonable to transition the gasoline shipping-and-pumping power delivery to hydrogen, but the primary benefit is just the zero-emission aspect (at the car itself at least). But today, chemical battery tech has progressed to the point that it's on the edge of full practicality, and hydrogen isn't really any closer to reality than in was in the 90s.