Red Skull is an integral figure in captain America lore and the Marvel comics, which is why the MCU needs to bring him back ...

that the MCU royally messed up. That bad guy is Christopher Eccleston's Malekith the Accursed from Thor: The Dark World. But why exactly did Malekith end up being such a nothingburger of a villain?

And that's why the MCU has, for better or for worse, made villains that always are worthy of matching up with our heroes.