With controversies like #OscarsSoWhite and the abundance of criticisms on directors' casting mostly white actors for roles sometimes even meant to be played by another race (take Scarlet Johansen's starring role of a Japanese half-cyborg in Ghost in the Shell), racial representation has been at the forefront of criticisms on Hollywood.

http://screencrush.com/ghost-in-the-shell-whitewashing-scarlett-johnasson-vfx/

Amidst the criticisms, Marvel has been doing something right when it comes to diversity in casting. 

Marvel writers and casters don't shy away from making their superheroes come from underrepresented backgrounds - from Ms. Marvel AKA Khamala Khan, a young Pakastani-American girl from Jersey City, NJ, all the way to underpinning a whole superhero narrative to the rule of African kingdoms in The Black Panther.

https://www.inverse.com/article/20651-ms-marvel-kamala-mcu-captain-marvel

The fantasy and sci-fi superhero narrative is juxtaposed with the very real human experience. Marvel is like the modern day the Greek play - the Gods and Goddesses have human-like qualities. Yet Marvel is able to reflect such human pitfalls and triumphs through a diverse cast. 


Some may question the importance of having racial diversity in a cast of superheroes in fictitious empires and realms. For the viewer here on Earth, the knowledge that culture and art includes you or those who look like you can empower and resonate with a variety of moviegoers. 


So for the viewer, representing different experiences transcends the silver screen. In the same way that art mimics reality, reality also mimics art.

http://www.superherohype.com/g00/news/401821-comic-con-100-thor-ragnarok-trailer-screenshots-will-rok-you?i10c.encReferrer=aHR0cHM6Ly93d3cuZ29vZ2xlLmNvbS8%3D

In Marvel films, the female characters can be villainous, heroic, funny and serious. There's a spectrum of humanity captured. 

https://www.buzzfeed.com/jaimieetkin/thor-ragnarok-comic-con-trailer

All the black characters aren't killed off, and the heroes aren't all white. This is actually important, meanwhile other films have fallen in such perfunctory tropes.

There's substance to the twists and turns the characters must endure, too. Comics can be written off as mere action plots, yet Marvel's writing is able to envision something greater about social realities, including more actors than just white men trying to save the world. 

Even with the culmination of heroes, villains, and laymen of different racial, gender, or galactic makeup, the characters ultimately impart common ideas, mysteries and fixations on the existential struggle.