The production and storage of hydrogen is expensive, had the downside of requiring a large tank in the car and is less efficient than just using a battery.
The cost will drop to nearly zero, just like the rest of renewable energy production. Tanks are cheaper, smaller and lighter than li-ion batteries. Fuel cell cars are also EVs, just like BEVs. The "efficiency problem" is greatly exaggerated.
Batteries will always been heavy and be dependent on large quantities of mined materials. The advantage of hydrogen is that it is made from water. So the raw materials used to make hydrogen will trend towards zero, similar to what happened with wind and solar.