So what if they change lives(they wouldn't save anyone they don't like or are friends with or interested in personally, unlike Superman or Spiderman), there still retarded and terribly bland protagonists, their not even funny. All they do is rely on so many people to get off suffering severe ramifications of their dumb plot luck lacking any sort of responsibility and common sense. Character Development wise, they are the same immature and short sighted child men they were since chapter and episode 1. It reflects the genre of the fucking demographic which manga authors think children especially little boys are simple and stupid idiots who lacks a good set of brain cells and wants to be a self insert of the protagonist as what they are personally. They along with Goku and Naruto and Gon etc are reasons why I kinda hate the shounen genre, it's nothing more than a personal stereotypical boy fantasy that puts all the exaggerated tropes on typical little boys and turns them into self righteous unrelateable mary suish self inserting retards with heroic elements pertaining to the so called innocence of a simple kid which is on par with god on a moral and pure scale.
While the side cast is fucking human and relateable the main protagonist has to be otherworldly and over the top aka more than anyone else and certainly better than all the fighters. Predetermined to win and yet because they are the main character they get to stay static and dull as shit because they need no development or growth due to being predetermined to automatically advance as the story moves on. The rivals and the love interests aka main female characters try to keep them human but all they do is provide and action and comedy aspects that really supplement the perfection of the main characters sub conscious of being greater than them as a rule. The female support characters get it worse IMO, they exist to empower the men as stupid yet illogical conqerors of the world and they are smart and logical weaklings who want to save or protect them by being bitches yet more affectionate, really sets back equal rights since women can't be as strong as guys and can't really effect a threat that even the main character has trouble with their comedy and drama devices, they have no sense of identity beyond being the girlfriend of the main lead or the love interest that is smart and resourceful but weak and a sign of fanservice.
The rival, well this one exists to be a whipping boy of the main lead in the same sense make the main lead seem less overpowered but IMO more a superior ideal to be than them plus the rival serves as the metaphorical trophy to win as proof to the main characters overall supremacy. To foil everything the main lead represents and does not, yet most all shonen show the rival to be extremely bitter and jealous to the point it's just self satisfying the main characters greatness over them. They can be friends or enemies, either way they fight because the main protagonist needs a equal of sorts or he'll seem to perfect and out of reach but then that fails since the rival is always someone who is more like us trying to match up with the god hero with a great destiny or skills fated by something to always succeed while the so called genius, prodigy, hardworking gentlemen, super tough realist, or very reasonable warrior aka experienced one is always second place to them based on fucking luck or being a total badass born to beat everyone. I think one of the cruelest things shonen has done is parody the rival as a need for a hero to be cooler than everyone and stronger than anyone because it shows how authors know that boys wish to strive to be in the drivers seats as the winner of the guy their facing and realistically they would lose, but rivals are more human and more in tune on how we feel more than the main character and realistically would act.
The villains need some say in this, but I continue that for another day.