Guild Wars 2

Base on my observation, most of the groups that does raids seldom bring along Thief/DD, I’m wondering why is this so… Seems like they all still prefers Ele / Necro over thief… Is just having pure dps not good enough to be taken in raids or are there some other reason that i’m not know of?

Thoef has quite high DPS but thats all he has, other classes have utilitys and stuff that helps with the boss and buffs the members of the squad.

Nope, just that we have no meaningful utility.
A ele can get DPS just under ours, but also has healing, Prot/Stab, Might, and plenty of auras, all of which makes them a better choice than just pure DPS.