The biggest problem with the Krypton movie is the same problem with ALL prequels - you know how it ends. Somehow, someway, no matter what variables you change, the fucker blows up.
All drama is gone. Everyone dies, except Kal El. It is unchanging. Great for a comic run, but one of the worst ideas for a summer blockbuster I have heard.
Audiences want Darkseid, or at least Brainiac. They dont want another natural disaster Superman has to save people from.
Superman is a hard sell. They have never EVER given Superman an antagonist more powerful than he. A huge no-no in storytelling terms. Superman needs to be outmatched for us to care, and he is simply too powerful and doesnt have the rogues gallery for that to happen. Personally, I think Superman should be de-powered by, like, ALOT. Back in the day, Superman could move planets. In the films, he can lift falling helicopters and the Statue of Liberty without a grimace. Even surrounded by - and impaled by - kryptonite, he could STILL lift a large island into space.
Come on. It should be difficult for him to lift a semi. Nearly impossible to lift a building or half a cruise liner. And his other powers - ice breath, super hearing, even x-ray, possibly even heat vision - should hve gone a lot time ago. He cant have EVERY superpower. He has no identity - he's just... the most powerful. At everything.
Superman in his first appearance couldnt even FLY. He DODGED bullets, they didnt ricochet off his eyeballs. Find a middle ground - make him the most powerful thing a human has ever seen, but not unstoppable. He really needs to think twice before stepping in front of a moving train or large explosion.
Take away his strength and you make him more human. More relateable. That's precisely what he's always needed.