Originally Posted by Mr. Dent
Ehh, we're getting farther away from believable and into the territory of just what doesn't look silly on screen now with the characters you mentioned, tbh.
Now hold on. My main point is that these characters (superheroes in general but these specifically) in the comics would wear crazy costumes even if it wasn't required. But in the MCU, they are all given reasons.
Iron Man/War Machine/Iron Monger/Whiplash - self explanatory
The Mandarin - eccentric mentally depraved wealthy terrorist leader.
Captain America - Initially wore the costume to inspire Americans, continues to wear it to inspire the old-fashioned ideal of inspiring good.
Red Skull - Nazi science experiment gone wrong.
Thor/Loki/Malekith - wear finely crafted other-worldly armor ceremoniously and for battle.
Ant-Man - Will undoubtedly wear his costume to shrink along with his body and communicate with insects.
Falcon/Black Widow/Hawkeye/Nick Fury/Maria Hill - SHIELD uniforms mandated and designed for specific missions and skillsets.
Star Lord - mask and suit designed for a human in space and other hazardous environments
Rocket - mask and suit designed for a raccoon in space and other hazardous environments
Gamora/Drax - more alien clothing/armor
Groot - naked
Hulk/Abomination - mostly naked
I think what I'm saying is I'm glad that gone are the days of Richard Donner's Superman costume that served no purpose. No identity was hidden, no protection was given, aerodynamics likely weren't taken into account, it wasn't required for his super powers. Nothing. No purpose.
I'd argue the same about Burton/Schumacher's Batman costumes, Daredevil, Green Lantern, Thing, Dr. Doom and several other villains throughout CBM history. The MCU (alongside Mr. Nolan) on the other hand, does it right.