Mahle Chairman Arnd Franz says that building out a hydrogen infrastructure won't be possible without "blue" hydrogen made from fossil fuels.
I'm not convinced that hydrogen (green or otherwise) makes sense for powering transportation. I think it's best use case is in replacing fossil fuels in high-temperature industrial processes.
But theoretically the storage can scale well and it's relatively cheap, albeit who really knows about the price for storage since there are no at scale storages out there yet.
it's only zero emission if you use a fuel cell
What do you mean by this? However you burn it, it's zero emission, isn't it?
The single advantage hydrogen has over batteries is that the "refueling" is pretty much instantaneous. If charging infrastructure and technology improves, there will be no reason to bother with it anymore.
IIRC, pumping hydrogen is only fast if the pump has a substantial rest between vehicles. Get a line of FCEVs wanting filled and you're looking at filling times not much faster than charging a battery EV.