Marvel's heroes have complexities that make them adaptable to nearly anything. These heroes aren't all perfect, shining examples of heroism or have skeletons in their closet of all kinds. This has made reading about them much more interesting and has allowed creators to put these heroes in all kinds of stories. Over the years, many Marvel heroes found themselves in situations where their actions weren't always a hundred perfect heroic.
Source:https://www.cbr.com/marvel-heroes-better-as-villains/