You could have an energy "cache hierarchy" in a vehicle.

Fast but small - capacitor

Medium - battery

Slow but large - fuel cell

Of course it would be quite expensive to build such a complicated car. Rather probably just a big battery will provide a good enough compromise. It might make sense for some very high use rate vehicles like buses or trucks. The capacitor could store energy for one accelaration from standstill to 30 m/s. (Or storing that braking energy). Batteries and capacitors get better every year too, so the tradeoff points are moving. For the fuel cell you could use power paste. It's much more expensive than electricity and requires special infrastructure, but it could be fast to fuel which could be a good tradeoff in some situations.

Effectively yes; the fuelcell itself is less complicated than ICE (well, probably not today, but it feels like that's an issue of one having been mass produced in incredulous quantities for a century and the other just barely out of the labs), but they both just make a disk rotate, effectively.