Red Son Superman is not the same as Injustice Superman. Red Son Superman is shown at various times to still posses the heroic core of Superman. He refuses to conquer the world through force, instead he tries to convince people over to his side through showing off the benefits of communism. Furthermore he clearly is able to see when he’s lost his way as evidenced by the ending. He realizes he’s gone too far and stops.

Overman is the same. He clearly loathes the world he helped make and actually tried to shut down the death camps iirc. He realizes that he is the bad guy and it’s implied he’s the mole helping the Freedom Fighters. Despite being a Nazi he appears fairly well composed and isn’t an over the top stereotypical bad guy.

Injustice Superman has none of that. People frequently beat you over the head with comparisons to Zod. He’s stereotypically evil and is incredibly stupid as well, constantly getting his ass kicked by Batman. He has none of the eloquence of Red Son not the regret of Overman. He’s a pathetic manchild in every one of his appearances and NRS makes it clear he’s the bad guy. He’s there to get beaten up by Batman and that’s it. He’s mildly less godawful than Injustice WW, but the contempt for the character shines through. He exists only to shill Batman as the “true” greatest hero, nothing more.

Also Joker is wrong about “one bad day” for reasons I already laid out in an earlier post. He’s wrong in the Killing Joke. He’s wrong in The Dark Knight. He is clearly not meant to be right. Only underage edgelords actually think the Joker has a valid point. A pity that NRS is composed of such people and that is the only AAA Superman video game we get.