Destiny 2 launched in September 2017, almost five years ago, as a sequel to Bungie's first space-magic looter-shooter that debuted back in 2014. Destiny 2's existence was not something Bungie fully committed to in the beginning because the company wished to keep expanding Destiny instead, but a sequel was meant to be a relaunch of the franchise across all platforms with new ideas. The franchise has changed a lot since its inception, and it is safe to say that Destiny 2's Year 4 and what has been shown of Year 5 are leaps and bounds better than the vanilla launch experience.
There were major changes to the structure of the game, with the seasonal model being introduced to replace DLC that showed its trappings with Curse of Osiris and Warmind. Seasons are a great way for Destiny 2 to grow and explore new stories and approaches to gameplay while continuing the legacy of the first entry, especially accompanied by big yearly expansions such as The Witch Queen and Beyond Light. However, the game cannot grow forever due to technical limitations that are already showing, which poses a question as to what Bungie hopes to accomplish with decades of content.
Why Destiny 2 Can't Take Decades of Content
A recent job opening at Bungie popped up for a Destiny Narrative Director role, and its description states that the candidate should be "firmly planting stakes in the ground for fans to enjoy for decades to come." It makes sense that Bungie wants to expand Destiny 2, seeing how it's a one-of-a-kind game, and seeing how the company promised that the game would continue to get new content after The Final Shape expansion. The Final Shape is supposed to end the Light and Darkness saga of the franchise, leaving room for more mysteries in the Destiny universe.
However, the problem that Destiny 2 is facing right now is space, in the sense of how massive the game has become and how many locations and assets there are, some of which go largely unused. In order to keep the experience as smooth as possible, Bungie introduced the Destiny Content Vault in Beyond Light, taking away older locations from vanilla Destiny 2 that weren't used as much anymore - Mars, Titan, Io, Mercury, and more.
Because Destiny 2 can't physically support decades of content, proven by the Destiny Content Vault, it's possible that what Bungie means is a Destiny 3 could happen at some point. Old content is constantly being removed with expansions, and seasonal content goes away at the end of its expansion's life cycle, whereas the Vault in Destiny 2 has been having issues with space for years now that Bungie has yet to work out.
Be it a year or a few years after The Final Shape, Bungie will most likely have to hit the hard reset button and start working on Destiny 3, simply because it would become a gargantuan task to keep updating Destiny 2 instead. Furthermore, if new expansions and updates to Destiny 2 demand more space, the solution would be to remove even more content from the game, eventually leaving it bare-bones compared to what it has featured over the years. Destiny 3 could be a soft reboot of the franchise, this time exploring entirely new locations, which would indeed be able to offer at least a decade of content on its own.
Destiny 2 is available now for PC, PS4, PS5, Stadia, Xbox One, and Xbox Series X/S.