Interesting discussion and agree not sure governments will raise taxes to replace petrol excise.

Everything I've heard and read though seems to put electric well ahead of hydrogen on almost all counts for passenger cars i.e. Hydrogen cars won't overtake electric vehicles because they're hampered by the laws of science (theconversation.com) It all comes down to the extreme lack of enegy from creating hydrogen, converting it to liquid, then back to power.

Green hyrogen seems most likley as the solution for heavy transport such as planes, ships and perhaps very long distance travel.