[2020] Pure classes

So I was looking through classes in this game and I noticed you can actually double down on your class and chose it again at lvl 25. As a Permanent Rogue player I was wondering how good these "pure" builds are because from the look of things the hybrid builds seem to be more flexible and offer more utility overall.

one last question : will we have Rondel Daggers in this game ? because If i ever go the assassin build I would want one of those.