Holy paladins do not have any buffs that prot and ret cannot provide, and with the addition of shaman totems and bloodlust (called heroism for alliance), are just not as necessary.
In TBC, blizzard was really trying to nudge paladins away from being cloth wearing healbots because it was too out of keeping with their class fantasy (even for blizzard). They were never meant to be that, and only became so in vanilla because blizzard designed the game and it’s classes incorrectly. Holy paladins are are still common and powerful in tbc. They just didn’t have their overwhelming dominance as a healer, similar to what happened to fury warriors as dps.
Druids got new spells and talents in TBC, much better itemization, and their coefficients were adjusted. I could be wrong about this, but I BELIEVE they get their regular rez in TBC as well. All this came together to put them on par with priests.
Druid for tanking. Note that this was heavily disputed during BC. I still remember my guild’s warrior main tank, and me the druid off tank, hitting all the various raids.
We’d start with him tanking the main boss, because something something crushing blows. The problem is they didn’t actually understand what crushing blows were, or when they happened. After he died a few times I’d tank, and we’d clear the boss.
Druids could legit get up to 80% dodge. 4 out of 5 hits just missed me, and I had almost twice the hit points of a warrior. Yeah, you take the occasional big crushing blow, but we never wiped because of it and most of the time my healers just focused on the raid.
I cannot wait to dive into druid again. You weren’t the most amazing pvp class, but you were relevant and fun, and you were so good in pve, especially after being garbage in vanilla.
I recall watching a restro sdroood and a hunter in arena gear taking me and 6 7 others out In AV trying to cap a bunker. Granted 3 of us where low 50s but still we couldn’t touch them let alone kill them. I went back over and over and watched as they dismantled multiple attacks from small groups of us with ease.
As a rogue who played on a really crappy server and played arena, warrior is the best, druid is the best for healer, and 2v2 in arena that combo is incredibly stupid.
DPS: Rogue,Fury and warlock.
Heals: Shaman
Tank: Probably a warrior, though most guilds would run atleast 3-4 tanks and you need one of each for tier 6 content.
every healer is good. shamans are nutty cause of chain heal & lust. can’t really have enough of them, you definitely want 1 prot pally, warrior still the most straight forward maintank but any tank class can. lock/hunter own. mages are outshined later, melee are weak early on. you want 1 ret pally to keep up judgements. pretty much everything in tbc has a place, specs that are memes in vanilla you still want to bring atleast 1 for their buffs
Not sure what sever you were playing on, but enhancement shamans and ele shamans were in CRAZY demand in TBC. Heroism/bloodlust had no “sated” debuff in TBC. Which meant you as long as you had enough shamans you could endlessly chain bloodlust on the raid. bloodlust/heroism was also party wide not raid wide, so a minimum of 5 shamans for most raids, and since healer spots are more limited dps shamans were amazing.
It was literally the meta in Sunwell to stack as many shamans as you could AND have as many war drums as you can to keep the raid endlessly bloodlusted for the entire encounter.
In BC alot of classes/specs became viable that weren’t in Classic/Vanilla.
Unlike in WoW where paladins are either just healers/support they can actually tank when they got taunt, however ret still sucked until Wrath.
So pretty much every class had 1 viable spec and most classes had 2 viable specs, come time Wrath nearly all specs were viable (if you had the right talents/glyphs and gear).
Paladin. Unlike Druids they can tank Illidan, unlike Warriors they can heal, they’re the kings for tanking 5-man content, their SP scaling makes them solid solo farmers, and while Ret isn’t as good as it was in WotLK, late TBC it was still very solid.
If not universal, it was at least super common. When i switched to my shaman as my main in tbc i was only allowed to raid as resto. The other raiding shaman was, you guessed it, also resto. I was never ever given a chance to go as dps. That was the “needs” of the raid team.
DPS: Hunters and warlocks (later on rogues with glaives)
Tank : Paladins are the only tanks capable of AE tanking (no target limits), this makes them perfect dungeon farm tanks and tanks in situations with AE.
Druids are great offtanks, have high threat and mitigation but cannot become uncrushable.
Warriors - arguably best and default raid tank.
Heals shaman, you want as many as you can get for bloodlust spam + Jesus beams and party totems.
That said, you want to cover as many buffs/debuffs as you can in TBC and there are support roles that do not exist in modern wow, you dont just stack the one best spec to the exclusions of all else.