Today lots of manga, I mean, paper printed editions, are published. Lots of readers would buy superheroes comics but.... the current fandom doesn't like very much the type of stories today are being published. Lots of readers don't feel welcome when they spend their money for a comic where the writter has got a different point of view about who are the good or the bad guys. The society of 2021 isn't like the generation who bought "Preacher" comics. And this is not only about comics, but also a growing reject against all Hollywood. Today the current potential fanboys don't feel identified with fictional characters who are too perfect, too handsome and never make mistakes. Today a gamer used to the shooter multiplayers who watchs a old far west movie can't believe the bad guys with a markmanship so horrible, even when old guns had got worse precision. And today other "indie" comic publishers are making enough money to survive at least, and some titles even have been adapted into action-live productions, for example Umbrella Academy or "the boys". Nor DC neither Marvel are selling the right product.
My suggestion is to publish motion webcomics in internet, at least something like "demo" or free-to-play equivalent, and enough "family-friendly". Then if those characters start to become popular the fandom will buy merchandising products.