Hmmmm, every modern film adaptation (i.e. Noughties onwards) of superheroes that I've seen that has been considered any good hasn't used the traditional costume. The ones that have have generally been considered crap, even when some effort has been made to keep the older style (Green Lantern, for example). I'm not saying this is causation, but there's certainly that coincidence there even without the cause and effect.
Look at the highest grossing superhero movies of the past few years. The Dark Knight trilogy - everything grounded in realistic science, the costume still similar to the comics yet clearly different, and more in the sense of military body armour rather than the crazy ass Golden Age comics stuff. The X-Men films - relatively normal clothes, with suits in combat that fit the setting and abilities of each. Badass look rather than camp like in the comics. First Class would be the exception, but even then the campness isn't exaggerated and is referenced with a sort of 'Hell No' by characters. Spiderman - still like the original comics, yes, but the distinctive look and serious attitude of the films all make sense with regards to the setting, and the look isn't camp by a long shot.
The Avengers films so far as well avoid campness. Thor looks like that because it's traditional Asgardian dress. Iron Man looks badass, not camp or silly. SHIELD agents look relatively normal or badass, save for Hawkeye, who can be excused because it's still much less camp than the comics. Captain America comes from a different era and when he does wear his old costume in the modern day it's specifically as a homage and reminder to him of what he once fought for. The Hulk is excluded from costume debates, of course.
On the whole, I don't see your point at all when applied to any of the actual good superhero movies. Regarding Logan, he does reference the traditional costume he wears in the comics in the first X-Men movie when they give it him and he basically says 'there's no fucking way I'm wearing that thing', as it were. But yeah, nothing I've seen is too silly, or silly without a reason. It does depend on how serious the movie is trying to be, however, as my point does apply more to films like Batman rather than films like The Avengers, but nevertheless the base point still stands.
