In the previous film, Finn, a Stormtrooper turned rebel, and his mechanic love interest Rose, played by Kelly Marie Tran, were sent off on a secret mission away from the main action of the movie.
Speaking on The Hollywood Reporter's Hollywood Remixed podcast the star revealed he feels his character was sidelined, and his and Rose's relationship underexplored.
"I liked the idea of these characters being challenged and separated and stressed, like everyone's just trying to get to each other," he said of the film. "That excited me. But I will be honest in saying... I think that they could have done better with it, especially with Finn and Rose."
Expanding on his views, he added, "You know, as a black person, you're going to feel a big type of weight. You had nothing to do with Rey and Kylo... (and) the story just wasn't here for me, with Finn and Rose."
John is happier with Finn's story in the new film, "The Rise of Skywalker", the last in the current trilogy, as he says director J.J. Abrams allowed him to bring out a stronger side to his character.
"Over the years I've gotten to know Finn much more," he explained. "Most of the time you're just waiting to hear what the writer has put to page when considering your character, and for me on this one, one thing I did want through this whole transition was for Finn to elevate and to advance; to definitely be much more strong, have much more confidence.
"Star Wars: The Rise of Skywalker" debuts in cinemas on Thursday, December 19.