I agree with the general idea of your post, but I disagree with this. MoPâs class design was persistently bad from a bigger picture. The reasons lay in that every role had the same tools to deal with all but the most niche situations, rendering every class very much the same outside of looks.
It wasnât something youâd notice if you only played a few classes, but if you looked at each one of each role, youâd see they all mirrored each other in a most uncanny way. Casters, for instance, all had a instant-cast spell for knocking down totems, and a way to freely cast while moving. MoP was a time of extreme homogenization, in a way that it only felt good if you only played a few characters. Your choice in what you played really didnât matterâŚuntil it came to numbers and utility.
You see, when every class has the same core tools, there will be a few that rise above the rest through some means, and therefor become better than everyone else. Warriors with banners, destro locks with copious amounts of raid utility(as well as the best ST and AoE, being tankier than plate melee, and the additional value of ranged in an expansion full of anti-melee mechanics for the whole expansion), blood DKâs with SR+vengeance stacking making them simultaneously the best tanks and melee DPS, paladins with many hands and the new devo aura for all specs.
Aside from these few notable specs(or classes in the case of paladin), no one else brought anything unique or interesting to the table. Itâs very similar to the problems we have now, and have had since MoP.
The whole point of picking a class in an RPG isnât just to pick another color, but to pick a select set of tools that only you have and no one else does, using them as appropriate. When one reduces the metrics of a class to nothing more than throughput, survivability, and mobility(via the most desirable-to-clear content), then you effectively eliminate classes entirely, rendering the playerâs choice in what they picked both without benefit, and inconsequential. Both of which, are necessary.
For class design to become truly unique and meaningful, what first must change is the outside world. The endgame must become far less static in its âmetaâ, breaking the mold of current compositions/rosters/what have you. Only then will there give rise for classes to also change, giving them useful abilities(and weaknesses against) for the game that actually matter.