Rockstar Games shelved various GTA 5 expansions due to the massive success of GTA Online, according to a former developer. Dataminers previously found evidence suggesting three different DLC packs were in development for GTA 5, including Agent Trevor, Alien Invasion, and Zombie Apocalypse. Steve Ogg, who portrayed Trevor in GTA 5, confirmed that a "James Bond Trevor" DLC was in development before the studio abruptly canceled it. Ogg mentioned that they had shot some content for this DLC, but it was eventually scrapped.
Former Rockstar Games developer James Rubino explained that the sudden success of GTA Online led to the cancellation of these expansions. Rubino, who worked on the Agent Trevor DLC and GTA Online, shared that the development team was split, with some members working on GTA Online and others on the DLC. However, the overwhelming popularity and profitability of GTA Online made it difficult to justify continuing with standalone DLCs. Rubino believes that, in hindsight, it might have been possible to do both, but it was ultimately a business decision to prioritize GTA Online.
Despite canceling the expansions, Rockstar didn't entirely waste the work done on the DLCs. Rubino mentioned that many elements from the canceled expansions were integrated into later iterations of GTA Online. Additionally, behind-the-scenes documentary footage was filmed throughout GTA 5's development, but Rockstar has yet to release any of this footage. The decision to focus on GTA Online proved to be financially successful, even though it meant shelving other creative projects.