Affliction is fin eif not overpowered on AOE, which is the only thing that makes it good for Mythic +
However, there are plenty of other classes almost as good, and they do much better single target, and that's the damage I was talking about. It really doesn;t help that locks in general but particulaly afflict gets pidgeonholed by it;s talents. You absolutely must take Sow the Seeds to do AOE. And it's better to take Sacrifice too. Both of those make a bug hole in affliction's already woeful single target
And affliction is great at aoe, sure, but when the week's modifier is Raging, and spam aoe'ing is a good way to murder your tanks or at least overstress your healer....plus you have to start thinking about whether you group has enough single target dps to carry the afflock during the boss fights. And you start to think about whether it woul dbe better to take a mage or demon hunter, both of which can pull excellent aoe and much better single target than affliction, not least because they can talent for aoe with much lower single target losses than affliction can
I'd love to hear warlocks are doing well. They aren't, though. The best you can say about them is that they require much more skill and effort to deliver mediocre rewards, and the way things are going, specswapping is gong to be a thing, what other class has to do that?
And if you look, the post I quoted does NOT include affliction. The poster was doing logs for mythic Nythendra and stated they could not find one for affliction.
Affliction just feels like a one trick pony, sure, it;s good at AOE in mythic + dungeons where the mobs are long enough lived, but what else is it good at? And evern this value will be degraded by increasing gea rlevels in other classes, as stuff will be burst aoe down, like it already is in normal/heroic modes and begingging to be in normal mythic modes too.
Affliction's single target is just way too low, this issue is partly due to the fact that Soul Flame does nothing whatever for single target, Wrath only does if you have a stream of adds to keep up the buff, and Reap Soul is tied to a supply of tormented souls
Affliction is extremely imbalanced, not least because the artifact is heavily tilted towards boosting affliction where it's already strong and providing little where it is weak.
It a single target fight like Nythendra, Soul Flame is utterly useless, Wrath is utterly useless, and you are starved of tormented souls to power up Reap as well - the self-proc rate is way too low.
The artifact is very obviously designed around the original Reap mechanics, where Ulthalesh itself provided those "adds" so you wouldn't be starved of self-buffs. But then they ripped that out and neve rmodified the rest of the talents to mitigate doing so.