Trash mobs make up 90% of the enemies you face whatever you do in PvE, so a way to kill large numbers quickly is amazing whatever you do, a striker can take out an entire wave of supplicants in the atheon fight with his super. with the exception of the lightswitch modifier pretty much everything requires two hits or more to melee you, leaving you with room to step in, take a hit, and punch that mob down or grab the mob's attention and step out of range again. As for the ward of dawn, as useful as those buffs can be, in most situations the shield is more of a hindrance than anything, getting attacked by a praetorian? Someone bubbles and sure your not taking damage but now you can't shoot him without one of you stepping through the bubble, either way the praetorian closes the distance and its his melee that's the real killer, and those buffs while nice are far from essential.