Yes, sorry. It should've been per litre. (https://en.wikipedia.org/wiki/Energy_density#In_chemical_rea...) The intuition about volume/ weight is out of the window with hydrogen, because it's so light. Thank you for the correction.

Of course, for almost all uses, the volumetric efficiency is important because you have to create bigger tanks, which if they have to contain liquid hydrogen, are usually heavy and costly.