It's seen you don't see the real problem, as a warlock a pure dps class with should compete with others pure dps class like mages,hunters, rogues if we cant do our roles and our utility is not so great compared to others class(our battle res is not instant and our portals have a 2 min cd to use it again, and our warlock stone can be replaced by healing pots) now mechanic speaking is more a subjective thing for every player, for example you have the s2m build to spriest that not everyone like it but at least in numbers they are doing more great that most of the specs of the game.
Are you drug or what? We are useless for two bosses in trial of valor that is much show how bad is the performance of the class in fights with many adds or single target without any cleave with wreak havoc, also get 90% percentile is not really hard if you follow the rotation and if you do the homework to learn properly the class you are playing
https://www.warcraftlogs.com/statistics/12#boss=2008
75% Heyla and affliction is not even there