Superheroes don't need saving. Superheroes do the saving. At least, that's the general idea.
They are an idea as old as humanity, from Gilgamesh, Heracles, Perseus, Sigfried et al. Incredible beings with extraordinary abilities, defeating even more horrific monstrous foes, often with a moral at the end of the tale.
And truly there's nothing wrong with the Superhero genre as it stands in pop culture. It's just that the MCU raised the bar so high it couldn't manage the expectations it set itself. We had 20 movies creating this awesome super-team that was set to save the world and they shit the bed when they delivered Endgame, and clearly have lost the sense of direction they had when they brought us Avengers and Age of Ultron & GotG.
Warner bros haven't come close with their DC offerings and even the X Franchise got worn out and delivered its death knell with Dark Phoenix.
It's not that Superheroes are bad - they are kind of niche - and Marvel got the world and his dog wanting to see the denouement of the Avengers arc which was disappointing in the extreme and they've failed to follow it up with anything meaningful. There'll likely be a pause and we'll get some junk farmed out to us, and then some bright spark will have an idea, get the budget to bring their dream to life and suddenly everyone will be saying "Yay, superheroes! Aren't they brilliant?"
It's not the superhero problem it's just long running franchise fatigue syndrome. It happens a lot. Take Star Wars, take James Bond, take any story produced over many years and they have highs and lows.
City of Heroes will simply be the candle in the window letting the folks out there know there's always a bright flame for those who want to find it.