It’s pointless if the hydrogen is initially coming from cracking hydrocarbons in the first place – and the dirty secret of the hydrogen industry is that it is – so it doesn’t really get used much. Similarly, if you’re still allowed to just make gasoline from oil, it can’t compete.
It’s not a new or experimental thing, though. The Nazis used it in WWII to make liquid fuel from wood gas to overcome petroleum shortages. It would become viable (in peacetime) only if we quit allowing fossil fuels to undercut it on price.