I come from the aerospace world, where we understand there is a real difference between something that cannot be done, & something that is prohibitively difficult/ expensive at present. My impression is that issues with H2 are the latter, not the former. Any number of things could change its status.
Going by the pod above, Joe Romm, a physicist, pretty much agrees with that take. Careful to say: ‘nothing’s impossible’, but that is a long distance from, ‘we should invest public funds in this’ and/or rely on this as the likely answer. Seriously focus on cleaning up fertiliser production alone 1st