Fun stuff to do...

[Aegis]

If I do dungeons or primals, I do it for two reason. First - to clear the content. Second to get the loot or whatever reward there is to get. What's the point in doing it as another class?
I'm far from burned out, there are still many things I enjoy doing in the game. But honestly, I'd rather quit than go through it all again just for the sake of doing it on another class.

If you're only doing content to complete it or to get rewards, you may need to look at why you play MMOs in general. The games you are playing should be fun in and of themselves. You should be smiling as you dodge plumes/landslides etc. Playing the game should be enjoyable in its own right. Not just a means to a reward.