One of the biggest misconceptions from many who create superhero films is that the costumes from the comics need to be "updated" in order to fit the big screen. While on a technical level, there is a level of design and redesign in making physical costumes out of comic book illustrations, it has recently resulted in many over-designed and unappealing costumes. In fact, the biggest cases of poorly designed costumes have come from the DC Extended Universe and the Marvel Cinematic Universe.
It's strange because the successful templates are right there in the pages of the comics. Sure, many comic book costumes are goofy, but that is the appeal. Characters with silly outfits are for children to enjoy, but film adaptations often focus too much on making the costumes "realistic" to fit a live-action setting.
When looking at the early attempts at bringing certain superheroes to the big screen, costumes that looked like the characters leaped right out from the pages of the comics were the most iconic. There is a reason why Christopher Reeve's Superman costume and Tobey Maguire's Spider-Man costume are still beloved to this day, while 20th Century Fox's early X-Men outfits got forgotten. Superman and Spider-Man did not look realistic, but that didn't matter because they looked incredible.
Indeed, with the subsequent Garfield and Holland starring Spider-Man reboots, the studios attempted to make the Spider-Man costume fit a more realistic aesthetic. In The Amazing Spider-Man, the film made justification after justification for how Spider-Man could make a realistic-looking costume while sacrificing the suit's appeal. The costume for the first film had a rough, unappealing look to it, and the familiar white lenses got replaced with dark sunglass lenses. But if ever there was a clearer admission that the original design didn't work, by The Amazing Spider-Man 2, it got replaced by a much more appealing and comics-accurate suit.
Similarly, the Marvel Cinematic Universe's Spider-Man started with a rough and ready "homemade" costume that didn't look like the comics. Instead, Civil War and Homecoming seemed to imply that, for Spider-Man to have an outfit vaguely similar to the comics, he needed billions of Tony Stark's wealth and resources. The MCU "Stark" suits for Spider-Man are prime examples of over-designed costumes, with extra lines and colors that make the costumes a visual mess. And in a similar admission to the Amazing films, No Way Home gives Spider-Man the perfect costume, proving that Marvel spent several other films overthinking the design.
That was a small microcosm of how these films have avoided the naturally goofy costumes these characters deserve. That said, all is not lost. While Shang-Chi's MCU costume seems impractical for martial arts, and the Eternals' costumes are a visual overload, small steps are getting made. Aquaman's final outfit in his solo film was perfect, Doctor Strange's costume has never gone wrong in the MCU, and Sam Wilson's Captain America looks like he's flown right out of the comics. Studios need to stop being afraid and fully embrace the lovable and goofy nature of the world's comic book heroes.