Quote Originally Posted by roninoftagrm View Post
...why do quests for new actions when there can be a new exp bar specific to this, like a mastery or proficiency system...
There are a number of reasons for doing this system as a nonlinear series of quests. First, it would create a tree of options while using all of the mechanics already present in the game, which is really easy for devs to implement and test. Second, it would keep it down to simple choices of which quest and subsequent reward you want at the moment, and even if you check online as most do, new skills and quests can be added at any part of the tree so devs can adjust it as time goes on.