Destiny is a game of grinding and gear, with players leveraging every system in the game to try to earn the best possible equipment to get to the level cap and begin the upcoming new for-pay raids. This work, which can appear tedious if you're not into that sort of thing, won't be wasted when the game's sequel is released: Your character and their progression will carry over.
"The idea is that the Guardian you have created is something you can bring along with you on that adventure." Bungie's David "DeeJ" Dague told IGN. "If you take a look at the way people have played other games for a long period of time, they've had a relationship with the same character for a very long time."
This may sound a bit ambiguous, but Bungie later said once again that everyone you do now will matter in the sequel. "Bungie has clarified with IGN even further saying that yes, your progress will 100 percent carry over to the sequel," the story's update stated.
We've known about the sequel for a while now, and the investment Activision has made in the game and Bungie only makes sense if it launches a franchise of multiple games, each with its own expansions and for-pay content. Keeping players locked into their characters, and feeling ownership over their loot and gear, is a great way to make those players feel invested into the series as a whole.
The gear and loot system has already seen some hefty updates, and the way players earn and upgrade gear will likely continue to evolve as the game ages. Your weapons won't become obsolete, there will just always be something else to work towards. The treadmill only makes sense if its constantly feeding players new rewards, even if those rewards will be persistent from game to game.