Hydrogen is usefull not as a SOURCE of energy, but as a method of transferring that energy from one place to another.
If we had better batteries we could use electric cars but because batteries are big and expensive and the energy density isn't that high, we look to other things like hydrogen.
But as has been covered, there's a lot of incorrect thinking about the topic, particularily by people who see a short youtube video of horrible "science " reporting and instantly think our energy problems are solved.
One thing I've read about recently is the use of sodium boro-hydride to store the hydrogen. It's an aqueous solution at atmospheric pressure so there's no need for high pressure cylinders or need to liquify the hydrogen. They pass the solution through a catalyst to release the hydrogen and the leftover is benign. It's really expensive so far though.