Fuels like gasoline and kerosene are cheap because they are energy dense products that we just need to pull out of the ground and clean up. Fuels like hydrogen are more expensive because we need to invest the energy that is later extracted by burning or through fuel cells. We technically can use electricity to split water to generate hydrogen, but that process takes electricity, which costs money.

Isn't the extra insulation specifically for liquid hydrogen? I would expect an airplane to be more like a hydrogen powered car and take compressed gas, not liquid.