Hydrogen fuel cell stack technology in vehicles

Dramatically different. The business case is weak even when the technology exists (eg Toyota Mirai).

Hydrogen is incredibly difficult to transport. The autoignition temperature for hydrogen is lower than many other chemicals utilized in transportation, which makes it even more dangerous than transporting flammables like Petrol.

The methods are also complex - liquefaction requires cryogenics, tankers (aka tube trailers) require compression, gas pipelines need capex.

Most places which need hydrogen in large volumes (eg petroleum refineries) prefer to setup captive plants.