Others have covered it in more depth, but the fundamental issues with hydrogen are:

1) generation (very inefficient, or generates tons of carbon)

2) storage, both offline and in vehicles (very expensive, dangerous, heavy, very inefficient, or a combination thereof)

3) transport (same, due mostly to 2)

4) usage efficiency (not bad with a fuel cell but still not great)

5) power density (fuel cells have low power to weight which is why no-one uses the generated power directly)

6) fuel cell lifetime (fuel cells don't last that long)

7) fuel cell cost

I've held this opinion since the best EVs were using Optima Yellowtop PbA batteries and Mr. Musk over there was working at Paypal.