Donkey Kong and Mario go way back, from Donkey Kong (technically, but we’ll get into that later), the Mario vs. Donkey Kong series, and all the sporting events, Super Smash Bros. and Olympic games. One place you don’t really see Donkey Kong and Mario interact, however, is the Super Mario games, in which he’s practically non-existent. Donkey Kong isn’t someone one regularly sees in the Mushroom Kingdom, especially when Mario is going through one of his classic duels with Bowser.
Article source: https://www.cinemablend.com/news/2574201/super-mario-bros-why-weird-donkey-kong-in-movie-seth-rogen