If the traits were such that your whole party gained Fury when you went into death shroud or your whole party got Might when you did your DS auto-attack; or your whole party gained Protection when went into DS... in those cases I could the necro bringing something unique to the table. A way to stack party-wide perma Fury and Might without a warrior would be something very interesting indeed. Probably still not as good as a warrior but it would be something.
That's true for fractals where there are high levels of play where everything must be min/max, and it's more a question of what players can do to give themselves a little extra push, and survivability is largely thrown out the window because if you get hit you're dead anyways. In all other explorables boon and condition manipulation can be very important. TA & HotW are good examples of this, conditions to remove off party members, boons to strip off enemies.
Fractals was a really cool idea, but sadly a couple profession mechanics kinda screwed it into something stupid rather than be something super cool that inspired creativity and build diversity to overcome problems.