FFXI was basically the EQ1 style of MMO, though. WoW, post Vanilla, started to stray away from that model. And they did so for some legitimate reasons
1) While resistance gear/specialized armor sounds cool on paper (Onyxia cloaks, NR gear for AQ40), it is just another time sink and forced itemization. With the NR gear, it felt especially bad because the only source of high level NR gear were the green dragons, which had limited spawns and were always in the middle of fucking nowhere. Consequently, everyone was forced to use NR gear 10+ levels below their current level just so they didn't insta-die on some of the AQ40 bosses. Combined with limited bag space and it isn't surprising the player base began to grumble about it
2) Weapons with unique combat effects, while cool, also severely limit your game design in the long term. If you choose to continue to offer them, then you are forced to design all encounters with the understanding that someone will have the weapon, which means you either nerf its effectiveness (which makes the weapon useless) or you make it mandatory (which adds another gear check gate bottleneck to the encounter, or forces you to use old gear).
FFXIV has shown you can have challenging raids without using specific niche gear as a work around. Yes, the regular content isn't very hard, but the Ultimate or Unreal content is very hard and have a very low threshhold for fuck ups that wont ultimately torpedo the attempt.