Compared to fuel yes. Compared to batteries, even at relatively low pressures, I think hydrogen still wins even by volume, and at higher pressures it's an order of magnitude difference.
> In Europe, battery powered trucks can carry a heavier load than diesel trucks.
You mean legally? If we're discussing which option is technologically superior long term, then it doesn't really make sense to argue based on arbitrary laws today. Is there a particular retionale behind the law that would make sense for electric trucks but not hydrogen ones?
> Green hydrogen is always going to cost about 10x as much as electricity.
Possibly, but as more renewable energy sources come online, the problem is going to change from "can we produce enough energy?" to "is the energy available at the right time and place?". Electrical energy is very difficult to store and transport in any significant quantity. We already have to turn off renewables sometimes because they're simply producing too much power when we don't need it. That power may as well go to creating hydrogen than doing nothing.
I don't know that hydrogen specficially will be the long term solution either (after all, something better could always materialize) but current battery technology is definitely not a panacea.
> ... is necessarily a lot less efficient than using than skipping 4 of those steps to charge a battery directly.
High battery/payload weight ratio means you need more energy to get where you're going, which is not typically considered when comparing the efficiency of batteries to hydrogen. Batteries also take a lot of energy to manufacture in the first place, and have a limited lifespan, which is also rarely considered. I think that with some minor efficiency improvements to a couple of steps, and a lowering cost of electricity at "off-peak" times, that the overall equation will shift.
> And truckers don't care about fuel density, they care about costs.
Costs come from a lot of places. Trucks sitting around charging instead of delivering goods are a cost. Reduced range means increased costs. Expensive batteries that have to be replaced every X years are a cost.