I wish content in this game would be more than just "kill X amount of things to finish Y instance".
For example, they could remove randomness of buffs/debuffs in Deep Dungeons and give players ability to control what's given, somewhat like in roguelike games.
Or add puzzles to dungeons so there would be more ways to finish the objective.

Instead we get the same formula over and over again, expansion after expansion, with no change.

"B-but you haven't finished all Eureka weapons" - lets pretend I did. Now what? What do I do with them? Put them into storage so they would take up free slots? I don't like how they look like so I don't want to use them as glamour. I also can't use them as a main weapon because it's an outdated equipment.
Before someone runs in screaming "IT'S AN MMO, GO AWAY IF YOU DON'T LIKE IT":
I've played enough years of MMO to get tired of mindless grinding. I get it, grind is a part of this genre and it probably should stay because there're always people who like this kind of thing. Grind becomes very unfun when there's nothing but grind around. "Oi, I've cleared this thing 10000 times and got this hairpin I won't ever use".
A change to certain things would be nice, even if it's a small change.