How? How do they play better in Wrath? The cata class design takes what works well in wrath, cleans it up and doubles down on it. They play ALMOST INDENTICALLY with a few quality of life improvements.
DEATH KNIGHT: Objectively better. SO much better. Rune system massively improved to prevent random resource spikes, trees much more focused with gameplay identities. No more “put up diseases, swap around some of the spells flavor wise” gameplay that every DK spec, DPS or tank, revolves around. DK is better in every way humanly possible. People will always remember DKs from WotLK because of the OP release, first new class and Arthas. But WotLK was a testing grounds for DKs. The real release is Cata, where they’re easily the most well - designed class.
DRUID: Feral slightly improves gameplay wise as a tank and DPS, though nothing major is added. Balance is so - so. Its more fleshed out but some people hate the eclipse system. Resto I would say is about the same, unless you loved being a tree. Druid stays the same.
HUNTER: Survival feels much better and really comes into its own in Cata. Its identity is far more fleshed out and the proc heavy gameplay shines. BM and MM barely change. Slightly improved in Cata.
MAGE: Arcane improves massively, being a spec that’s very easy to get started with but now possesses a lot of room for optimization. Fire is better because combustion in cata is STUPPPPPPPPPPPPID fun. Frost is a littttle bit better as well, maintaining a similar identity but getting a few fun new toys. Mage is improved in Cata.
PALADIN: Holy power is a huge W for Ret and Prot. No more “press the button when its off - cooldown” monkey gameplay. There’s an actual flow to both specs. Holy gets some cool new toys, but a combo point system for a healer makes it slightly worse than before. Overall, Pali is better.
PRIEST: No more “PW Shield in your PW Shield so you can PW Shield your PW Shield while your PW Shielding” Disc gameplay. Enormous improvement. Holy gains new toys, though not entirely practical toys. Shadow kind of stays the same but gets cool glowing purple orbs. Priest is better in Cata.
ROGUE: Almost identical to wrath, but Sub is improved quite a bit and finally starts to feel like more than “generic rogue, but PvP spec” (though its still the best PvP spec). Very little to say here. If you like Wrath Rogue, you’ll like Cata Rogue. Combat go brrrrr, Assa go poisssssson.
SHAMAN: Enhance and Resto are much, much better. Far more fleshed out variations of what they were. The visual update really helps Resto separate from Druid, as the “water” healer, and their identity as the big raid CD healer starts to take off. Elemental is kind of the same. Ridiculously simple lightning go brrrr and giant Lava Bursts. Shaman wins in Cata.
WARLOCK: The only class that I think gets a little bit worse. Demo is pretty much the same and Affliction is a bit different, but feels pretty similar gameplay wise. The outlier here is Destruction. There’s no way around it, Cataclysm Destruction is a disaster of unprecedented proportions. Every generic Warlock spell being a DPS increase for it just makes it dreadful to play, and it has more management than the management spec (Affliction). Locks are worse off in Cata.
WARRIOR: Prot plays almost the same. Arms plays MUCH MUCH better and really comes into its own in Cata. Really nails its “I hit slow, BUT HARD” fantasy. Fury is slightly worse. Its still fast paced, but Blood Thrist, X, Bloodthirst, X, Bloodthirst" gets pretty tiresome. Warrior is sligggghtly improved because of Arms.
Compared to how they play in Wrath, I think you would be hard pressed to make an argument that Death Knights, Mages, Shamans, Paladins and Priests are much better from a design standpoint. Warriors, Druids, Hunters and Rogues don’t change much but are slightly improved because of a few new toys. Warlock is imo, the only class a reasonable and objective person could look at and say “that’s a downgrade”.
If you sincerely believe that Wrath Classes play better, I would absolutely be willing to hear the reasons why. Not hyperbole, but genuinely, objective changes that make them worse in Cata.
If all you can do is respond with a “hollow” remark that doesn’t in anyway backup your belief that they play better in Wrath, you’re simply proving my point. “Wrath is better because it is” is a very, VERY poor argument.