For the most part, some of “Superman” is simply who Clark is. Red Son Superman for example still retains the idealism and optimism of Superman, even abiding by a no kill rule (that showcases why not killing people isn’t intrinsically morally superior if that’s all you feel obligated to follow). Overman, who was raised by Hitler, still retains enough of a moral core to realize “oh s*** I’m the bad guy” even if by the time he realizes it, it’s far too late to save his soul.
The Nail shows a Superman who wasn’t raised by the Kents yet still managed to be a morally good person, he just lacked the same push to use his powers. There was an Elseworld where all of Krypton made it to Earth, and Kal still ended up siding with the humans and fighting to free them from Kryptonian oppression (by Christopher Priest). There was another Elseworld where Superman chose to use his powers to get rich, and even by the end of that he realized how empty that life was, and was on the road to becoming a hero.l by the end. Even the Superman raised by Darkseid ended up making a heel turn at the end I believe.
So there’s a nature aspect to Superman. However it’s the nurture of the Kents that help him reach his highest potential, and if Superman was raised by other people there’s a chance he could end up being similarly damaged as Homelander. Not the same, Homelander is an idiot, he gets by solely on brute force and that’s never been Superman’s deal outside some bad stories by people who don’t get what his deal is. But “Clark Luthor” of Smallville was a sociopath raised as he was by Lionel, and he as well as Ultraman are the most “Homelanderish” Supermen given they’re entitled narcissists who think they’re gods and view others as ants to be stepped on. Even the “evil” Supermen such as Justice Lord or Injustice Supermen aren’t like that, they’re still trying to “protect” people whereas Homelander doesn’t give a **** about other people at all, only himself.