[mattalex]

There are alternatives to iron that have higher efficiency and lower prices. For instance https://hydrogenious.net/ does exactly that but with benzene like structures. The advantage of this is that you can reuse existing infrastructure for transport and you have higher transport efficiency: while the square cube law exist, the same thing holds for the forces on the chamber walls which have to increase in thickness. Hydrogen tanks are also very expensive as they have to be manufactured to tight tolerances (and they need to be replaced rate often due to hydrogen creep weakening chamber walls)