Sorry, but you sound like you're paid by Toyota.

Producing green hydrogen isn't anything new - we did it in physics class in school. Maximizing efficiency isn't a new idea either, but there isn't a lot of gains on the front in the horizon.

And yes, Hydrogen-powered, Rocket-propelled space flight is absolutely a thing, but it doesn't have a lot in common with commercial passenger flight as we know it. Those rockets also have a pretty abysmal weight-to-payload factor.

I'm not saying we shouldn't use hydrogen (in fact I'm working for a company that makes elctrolysers for producing green hydrogen). But let's start with the low-hanging fruit: Steel production, fertiliser production. Things that doesn't move at 800 km/h.

Fully charged has more on the subject

Edit: wrong link