Hydrogen has a lot of potential as fuel (pun intended). The problem is transporting hydrogen to where it’s needed. Because the molecule is so much smaller leakage is a problem and there’s also hydrogen embrittlement to contend with.
Storage in metal hydrides is one soluton, but for aircraft that always return to specific locations, on-site hydrogen plants could generate the fuel on-site, as needed. That would eliminate transport concerns and once production was scaled to match consumption, minimal storage would be needed which minimizes boomablility.
The issue for passenger cars is more complex but truck fleets such as FedEx or WalMart trucks that operate out of a specific hub location would be feasible for on-site hydrogen production. All it takes is natural gas and we have lots of that and it can safely be transported.
Or just build a fleet of natural gas vehicles. Much cheaper, easier and safer.