I drove 1800 miles in a Hydrogen Car

Since this is essentially advertisement for this, they don't talk about the negatives.  No, I do not KNOW what they are but there certainly are some...Everything's a compromise.

One thing against batteries is that the environmental impact of fabricating, maintaining, and disposing of batteries (as well as other factors) almost outweigh the impacts using standard engines.  At least, this used to be the case ~20 years when they were trying to sell us on the idea.  I expect that today, it's nowhere near as bad.

I guess it's the pessimist in me.  When something seems too good to be true, there's usually a catch.  As much time needs to be spent on these videos detailing the disadvantages of this technology.  As with all newer technology, time will tell.