Dungeon Exp really needs a pretty big boost, specialy how other than to do the story mission quests you can totally avoid doing them because fates give 10x +++ exp dungeons do,
and don't say you do them for gear!
why you ask ?
because you can use white gear from quests and crafting to do fates because they are broken and a easymode powerlvling mode.
dungeons need a drastic exp boost to be on par with fates and so people will que for dungeons more often to lvl so there is a purpose for using them.