In recent times we’ve seen some good UH DK presense in M+, but the raid damage is still terrible. The only change so far in 8.2 is that they are fixing a pet bug(which lowers the overall damage) and a 6% pet dmg buff to compensate for it.
If you look at damage statistics for the last 2 raids(95th percentile as ref), Unholy is one of the worst performing classes along with arms warriors, sub rogues and marksman hunters. The single target damage is tragic, we have the same burst as destruction warlocks, but much less sustain, the biggest cooldown in our kit is 8 minutes and the only option to reduce it to make it reusable during a fight means losing the second best cooldown.
Unholy is a complicated spec to play compared to most other classes and specs (this can be seen by looking at lower percentile rankings where UH ranks lower, compared to mid parses, where it’s in the middle of the pack), and falls off compared to other classes(mid parses compared to high) not because of player incompetence, but because of lack of damage.
We REALLY need a single target damage increase to make the class viable. I don’t really care if this also means a small aoe nerf or talent re-ordering or pvp dmg scaling nerf.