That's a straw man, that's not the only thing which defines him but it is a big factor in his presentation - when Superman shows up to fight villains his other super-heroes and civilians get more optimistic since his presence is soothing, which isn't something unique to him. Now he's not a man of action, despite doing things like fighting alien invasions, dangerous robots and never ending supervillains who want him dead. Except it's not junk, super-heroes who don't inspire hope from people are terrible super-heroes, even anti-heroes are capable of doing this. Would you prefer people to bored or run away in fear of super-heroes when they show up instead?
It's not his show, they're not going to remake the series into being about Superman it'd be incredibly tone deaf on CW's part. It's not like Superman hasn't been a guest star in other media before and she is his cousin who he cares about. The fact Supergirl is a spin-off of Superman from the comics doesn't define her as being without worth, all that does is acknowledge her creation which proves nothing. Superman came first, so what? Except Supergirl isn't a failure, it's on its sixth series which is ending on its own terms, its not being cancelled because of bad ratings. So Superman shouldn't appear in any tv shows in the CW unless he's the star of it? That makes no sense. He's a big boy, he's perfectly fine taking the back seat to other characters in their own series, he's been doing longer than we've been alive. He doesn't need to hog all the spotlight all the time, that's the complete opposite of how Superman acts.As for CW "Superman" guy is playing second banana to a character who only exist because he was a success. That's an off the back failure regardless if it came packaged with a tv shows for taking a bunch of L's to get it. Lowering yourself to get a promotion really doesn't sound like Superman frankly.
But that would "outshine" the other character in question, especially if in the story they should be doing something better than he does, frankly making him the best at everything is incredibly boring and pushes everyone else into being redundant when they shouldn't be. Characters can have rivalries, and they can have specialities the others lack without being a rival. This has ben going on since the Silver Age, COIE didn't start every trope.I don't really believe in Superman trying to outshine any character but if that character is going out of it's way to try and challenge Superman then the Superman writers should crack down. But honestly prior to COIE this stuff wasn't much of a thing since saving lives and improving the world was the primary function of a character that was getting called a superhero. Post-COIE the point of being a hero has become proving that you're powerful and getting others to recognize that with saving lives a secondary point.
Superman also had a personality more than simply narrowly focusing on saving the world. He's curious, friendly and tries to understand how the world works. He is a reporter, after all.
Those fandoms are defined by legacies replacing older heroes, not who can beat who in a fight. That's the controversy.It why the writers have become so obsessed with proving whatever character they fanboy can take out some other character they care much less about, for example look at the interwarring among the Green Lanter fans or The Flash fans.
That's never going to happen because comics have a specific status quo to uphold, and he wasn't doing that prior to COIE. In the Silver Age they made excuses so the Justice Society couldn't impact the war so they bought in the Spear of Destiny to avoid fighting the Nazis. Which means inspiring hope, not alienating people when he shows up. Positive people like that inspire hope.Frankly one of the reasons I think Superman needs to be allowed to get more involved and actually make some significant changes to the DCU is because the Post-COIE writers lowered the bar of what it means to be a hero far too much and now we've got individuals like Harley Quinn lecturing Batman. Superman holding himself to a higher standard should mean more than just not killing or being polite, it should also mean having a profound positive impact on the world he's operating in.