Marvel embraced sci-fi storytelling in the Silver Age. DC had reinvigorated their superhero universe using science fiction as part of their blueprint, and Marvel copied them. Even the pre-Fantastic Four monster comics leaned into science fiction. Superheroes and sci-fi go together like chocolate and peanut butter, and Marvel has always kept that in mind when creating many of their greatest comics.
Source:https://www.cbr.com/marvel-comics-sci-fi-movie-wishlist/