Destiny, and GTA V in its own ways, are scaled down MMO's. Bungie prefers the term, "Shared World Shooter," but really it's a refined version of the MMO style of gameplay. There's just as many, if not more players, but the way how they're handled is different. We're all put into separate lobbies that we can leave and join as we please. Essentially, all the good parts of an MMO, but the chaos is under control.