The big problem with Hydrogen is that we are too far from a realistic solution. The climate emergency requires action now, and practical hydrogen is too far off. That's why manufacturers are developing battery cars. They aren't perfect, but they give us a route to the future.
Tim, I think if the politicians stopped focussing on battery powered vehicles for a moment and started planning for hydrogen the manufacturers would quickly switch resources and research into fuel cells. It seems to me that practical fuel cell cars are already available and it just needs serious input into infrastructure and mass production to reduce costs. As time passes the next generation will be even lighter and more efficient.