Destiny 3: 8 Reasons It Should Be Single Player
1. Bungie Could Go Full RPG
Combining all of the elements mentioned in the previous entries would lead to Bungie creating a fantastic RPG (if executed well, of course).
There have been rumblings that the third Destiny game will be going down more of a role-playing route anyway, but making the game single player would make it a far more effective one - as the studio would then be able to implement features such as choices with greater ease, rather than holding back simply to fit the online model.
Realistically, Bungie making Destiny 3 single player is never going to happen, though the studio should definitely endeavour to push the game as far into RPG territory as possible, as it is a direction that would really breathe a lot of new life into the series.