Comics are a wonderful thing. They take us to places we can only dream about and feature characters that are uncanny, spectacular, amazing, mighty, and more. Superhero comics are the pinnacle of this for many, and thus, we have a serious attachment to them, and want to see them portrayed in an “accurate” way when shown in media they’re a part of. For TV and movies though, this can be a problem.
Why? Well, despite how they may look at times, often, superhero costumes are unrealistic, overly simplistic, ridiculous, or just plain hard to make. Thus, when they transfer to TV or movies, they have to be altered. A great example of this is Green Arrow, who became Arrow in his CW/DC Comics TV series. The costume change was drastic from its origin. But, it worked because it fit the tone of the show. Furthermore, the original Green Arrow costume was basically a Robin Hood costume, not exactly good for attracting viewers.
Another great example is the X-Men. Usually, the X-Men all have unique outfits in the comics. But in the films, they’ve been portrayed as wearing more uniform like attire. Which again, works, because it makes sense. Though it does seem to have had an unusual casualty in the form of the classic Wolverine costume, you have to think whether it’s practical to have that pointed headpiece. It’s clear Logan doesn’t need it, so why make it?
Now, obviously there are exceptions. Batman, Thor, Superman, Dr. Strange, Wonder Woman even, they all have classic and iconic looks, so there’s more of an argument for them to resemble their comic book counterparts. But even then, some leeway is allowed. The Wonder Woman in the DCEU doesn’t have the “bathing suit” look like many classic interpretations. But, rather a look that fits an Amazon warrior. And it’s clear she’s still Wonder Woman. Batman is another great example. He’s had so many different looks in the comics, that you can literally pick and choose bits from each one, make a batsuit, and still be happy with it.
In the end, yes, superhero costumes are important. But, what’s just as important are the characters themselves. For a while, they may not “look” like them at times. If they don’t “act” like the hero, that’s a bigger crime.