An ever resounding yes, in pvp, a possible yes, but never no...
Reason? Criticals seem to be affected by armor levels. Wild blow a 60 AL dummy in IoN and then a 100AL. Critting a warrior type in PvE also results in damages of up to a whopping 33!!
In PvE, since AI = Artificial Incompetence, the deadly arts moving punish skill: Enduring Toxin, combined with Soul Barbs, makes for an easy killing kite build.
In PvP, DA gets its kicks from one term: undodgable. A large amount of the DA skills simply don't allow you to dodge and your effect is guarunteed. The enemy can't avoid your attacks, they can only hope to remove their effects later on.
Iron Palm and Entangling Asp come to mind.
Dancing Daggers does shitty damage you say? They do more damage then when you're blinded and hexed with Faintheartedness. They do more damage when you try going for your off-hand attack even though the enemy dodged the daggers [very odd mechanic in that the daggers don't all have to hit and the enemy still registers as being lead-attack ready]
Siphon Speed is the best snare in the game with high deadly arts. Your team will love you and you yourself will have an easier time tearing his hp down...
Deadly Arts ignore armor so it behaves kind of like a majority of Shadow and Holy elemental attacks. They don't do monster spike damage, but they do cause damage unavoidably.
And in the metagame, that's far more useful to me than high spike damage that can't land...