The Marvel Cinematic Universe is known for creating comic-accurate suits as far as possible, but Captain America's MCU suits leave out a crucial element. Captain America has appeared in multiple MCU films between 2011 and 2019, and his costume has changed for every film (and sometimes he even wears multiple suits in the same film). Unfortunately, a single critical component was ignored in every suit - with one possible exception.
Captain America's suit is almost entirely the same today as it was when the superhero debuted in Captain America Comics #1 in March 1941, and almost every key element transferred over to the next iteration. Red stripes across the torso, a single large star on the chest, red gloves and boots, and a white "A" on the forehead are all iconic elements (along with the wings on the sides of Captain America's helmet, though nowadays there are merely painted on the sides). Unfortunately, the one element lost in the transition from page to screen was something most superhero suits lack entirely in comics: texture.
Captain America's small, individual "scales" that adorn his chest (specifically the blue upper half of the suit) are known as spangles, something that Captain America actor Chris Evans' suits have gone without. Some fans have suggested these give off an appearance of a bald eagle, America's national bird. They are undoubtedly very time-consuming for any comic book artist to draw, but they're nevertheless an iconic staple of the character's appearance in comics.
Captain America: The First Avenger costume designer Anna B. Sheppard certainly had her work cut out for her in translating the bright and colorful suit to a real-world environment. She elected to borrow elements from Ultimate Captain America's suit, with pouches to hold ammunition, tan combat boots, and straps that suggested the signature red stripes instead of a simple image. The spangles, however, remained absent from every suit - until Avengers Endgame. The costume designer for Endgame, Judianna Makovsky, recreated the spangles on the upper body with indented armor patterning on the chest and shoulders. Unfortunately, the suit in Endgame was the last time viewers saw Steve Rogers don the uniform, and since Sam Wilson's costume in the comics eschews the spangles, it's likely his MCU counterpart will as well.
Fans of comics are incredibly particular when it comes to comic-accuracy of their favorite characters' suits (both the best and the worst costumes together). As well they should: as a visual medium, a costume as as much a part of a hero's identity as their name. While it's regrettable that the Star-Spangled Man lacked his spangles right up until his final appearance, the core characterization of Captain America in the comics has remained untouched.