I think the main problem with hydrogen in Airplanes is the storage. You need either insane pressure or extremely low temperature. Both is tricky for security... And energy density is low... As far as I know no one has technology wise a real edge over anybody else at the moment. We'll see how it turns out...
I think most people are still not aware that there even are European alternatives to big tech. And for alternatives to thrive people have to be informed. I would definitely say it's okay to use big tech too convince their users to switch sides! As you said on platforms like lemmy you mostly reach people who are already aware of this...
I think the main problem with hydrogen in Airplanes is the storage. You need either insane pressure or extremely low temperature. Both is tricky for security... And energy density is low... As far as I know no one has technology wise a real edge over anybody else at the moment. We'll see how it turns out...