Hydrogen’s small molecular size facilitates permeation through many conventional materials, leading to leakage and potential embrittlement of metals. These characteristics create "unique" (read: expensive) engineering challenges.

And if you store it as a liquid that's when you enter the whole cryogenic problem, seeing it needs to be cooled to over - 225c

Even with advanced insulation, liquid hydrogen storage experiences unavoidable boil-off at rates of 0.3-3% per day, creating both economic and safety challenges.

And if you could make hydrogen via electrolysis, even with some uber wunderful unobtanium catalyst then you're still just waiting electricity that we can store far more efficiently in batteries (and with sodium batteries hitting the market there is going to be a huge revolution in battery economics and tech that will make lithium look like a drop in the ocean.