>>536927932
I feel like vanilla isn't conducive to a good environment for auto parties.
The dungeon's level ranges are too wide, like getting a level 29 tank for SY GY and not having a curse dispeller for the 75% healing debuff.
That's ignoring the likelihood of you getting multiple warriors and paladins who quit on seeing another plate user.
I think it works better in TBC and Wotlk because despite, having the rough spot between the last expansions gear and the current expansions gear, the level ranges of all those dungeons are far more compact due to 8 dungeons being divided across 10 levels.
Even then, retail added that 15% buff because they realized these hodgepodge groups were failing more often than not.