Electric motors are actually a pretty good means of supplying torque to the drive wheels. Diesel-electric locomotives have long proven this means of power delivery for decades. Nothing wrong with that part of the technology.
The big bottleneck is the battery technology. While batteries have gotten both more efficient and reliable than they were in the past, they still do not have the range or the full capacity to deliver all available energy from fully charged to fully discharged.
Fuel cells, charged with hydrogen, overcome many of these difficulties, but introduce a number of others. One is the availability and another is on-board storage.
Hydrogen has two challenging characteristics. One is the extraction of hydrogen from other sources, as there are no hydrogen mines or hydrogen wells around. Another is, hydrogen is notoriously hard to store, as it leaks out through most EVERYTHING, and it is highly corrosive of most metal connectors, forming metallic hydrides, a very brittle series of compounds. And it must be kept under very high pressure, but never becomes liquid until very low temperatures are reached.
Three challenging characteristics:
I could really get into a car with a big ass diesel generator in the trunk.
No storage problems with that set-up.
The old WWII subs as well. They'd go out on a 90-day War Patrol and return with fuel left in the tanks.
I've often wondered why they couldn't be used in the highway tractor trailers or city buses. Perhaps an issue of scale.