Prior to 2015, the characters of Marvel Comics were split between three separate film studios: 20th Century Fox held the rights to X-Men and Fantastic Four characters; Sony Pictures had Spider-Man and a number of related villains and heroes; while Marvel Studios retained the rights to The Avengers and other comic book heroes like Guardians of the Galaxy. However, after The Amazing Spider-Man 2 didn't perform as well as Sony expected, both at the box office and with critics, the fate of the studio's Spider-Man universe was in question.
The situation surrounding the Spider-Man franchise was exacerbated by the Sony Pictures Entertainment hack of 2014. But, the hack also provided superhero fans with the first indication that a deal between Sony and Marvel was potentially in the works to bring Peter Parker into the Marvel Cinematic Universe. In early 2015, the partnership was officially announced and it was later revealed Spider-Man would appear in Captain America: Civil War before going on to star in a solo film, recently revealed to be titled Spider-Man: Homecoming. Now, those who worked on Captain America: Civil War talk about bringing Spider-Man into the MCU and how he helped the third Captain America film.
In an interview with the Hero Complex, Civil War co-director Joe Russo praised Marvel Studios head Kevin Feige and at-the-time Sony head Amy Pascal for collaborating on the unprecedented partnership. Additionally, Russo explained that Spider-Man helped the storytelling of Captain America: Civil War by the introducing a "free radical character" that added an unexpected element to the otherwise "predictable" storyline.
Furthermore, co-screenwriter Stephen McFeely spoke about the added benefit of Peter Parker's (Tom Holland) young age, while fellow screenwriter Christopher Markus explained how Spider-Man's different attitude in comparison to the other superheroes in Civil War helped to elevate the film:
The very point of the movie is the heroes, they’re having real problems with being superheroes now. They’re jaded and it’s encroaching on their lives and it’s not easy. And if you only have those people in the movie, then you’ve got a movie that is saying the thing the audience enjoys isn’t any fun. It’s like slapping their hands when they reach for the candy. It’s great to have a character, like Spider-Man, who’s brand new. Who’s still having a blast, he’s super-excited to be meeting Captain America for the first time, because it injects that kind of wonder back into the situation… You need an outside voice to shine a light on the things the people in the scene already know. [Black Widow is] not going to look at anybody with wide-eyed wonder.
Of course, Peter Parker's young age was apparent from his very first appearance in the second trailer for Captain America: Civil War. But, Peter's age and excitement about donning a super-suit alongside such famous heroes as Iron Man (Robert Downey Jr.) and Captain America (Chris Evans) go a long way to help establish the Spider-Man character in his first appearance in the MCU - offering a lighter, more comedic tone during his scenes, as Russo, McFeely, and Markus hint.
That being said, though Spider-Man has perhaps more screentime in Captain America: Civil War than fans were expecting when the partnership between Marvel and Sony was announced, viewers may not be able to get a full sense for the new iteration of Peter Parker until his standalone film arrives in 2017. However, with Spider-Man: Homecoming continuing the relationship between Peter Parker and Tony Stark as established in Civil War - since Downey Jr. has joined the cast - it seems the solo Spider-Man feature will further develop Holland's young version of the fan-favorite Marvel superhero.
Captain America: Civil War is in theaters now. Doctor Strange opens November 4, 2016; Guardians of the Galaxy Vol. 2 – May 5, 2017; Spider-Man: Homecoming – July 7, 2017; Thor: Ragnarok – November 3, 2017; Black Panther – February 16, 2018; Avengers: Infinity War Part 1 – May 4, 2018; Ant-Man and the Wasp – July 6, 2018; Captain Marvel – March 8, 2019; Avengers: Infinity War Part 2 – May 3, 2019; and as-yet untitled Marvel movies on July 12, 2019, and on May 1, July 10, and November 6 in 2020.
Source: Hero Complex