In my mind, animation is the natural home for superheroes. You don't have to worry as much about big budgets or special effects, and the medium is a natural fit for adapting the kinds of stories told in a lot of comic books. It also helps that I grew up in the Golden Age of superhero animation: "X-Men", "Spider-Man", and "Batman: The Animated Series", which is the best adaptation of Batman onto the screen, no I will not be taking questions, thank you for your time. Sorry, that's not the point. The point is that animation seems like the perfect place for an Avengers movie, and this film serves as a sort of soft launch before the massive undertaking that would become the MCU.