Truthfully, I think they were right to make Superman less American in character. But they were wrong in trying to internationalize him.
The bottom line is that he is an incredibly powerful alien being, who by dint of being an orphan raised by humans, thinks he belongs with us. He doesn’t. The best thing he can do to thank us for raising him would be to protect us from equally alien threats far beyond our ability to stop.
He cannot belong to our social contract, nor can he engage us in any practical way. If he stops a thief, and “turns him over to the police”, they almost certainly have to let him go, unless he has an outstanding warrant unrelated to his current crime.
Legally, he is the same as a wild animal.
how have you already seen the movie?