Remember how it was said early on that visions were given to potential archons, yet to this date no archon has come from the ranks of vision holders?
That's because it's a lie. The purpose of the vision is the redistribute the authority of the dragons and carry out surveilance of vision holders. The users will during their lives learn to use the elements and grow the shard of authority with their mastery. Then when they die the shard returns to the throne and its power grows. Raiden had it all wrong.