Unlike all other proactive defensive options, Barrier has its effectiveness cut by Agony. Having Agony on you means any Barrier you receive is cut by 70%, just like healing.
However, I've been informed that it is even worse. For Barrier, this cut is compounding for each stack of Agony, to the point where 5 stacks will diminish any Barrier gained to a single point (barrier value of 1).
So, to the devs, is Barrier supposed to be meaningless in higher tier Fractals?
Plague Signet is the only skill in the game that is worse when traited.