>>105620542 (OP)>what were Japanese thinkingJapan was largely ahead of the West in Hybrid power trains. and FCEV technology lines up with hybrid powertrain design.
The electric motor is driven by a constant source of power, and a small battery is used to provide peak output and kinetic energy recovery.
If batteries had stayed $1000 a kWh, the cost of fuel cells had come down, and hydrogen had gotten fossil fuel style subsidies FCEVs may have made sense.
Unfortunately for hydrogen, fossil fuel companies have fought anything else getting subsidies, and BEVs are the only thing that can survive without them.
The cost of batteries has also dropped far more quickly than the cost of fuel cell stacks.