Is wow difficulty hard though? Normal and heroic modes are already pretty beatable even in the half ass gear we have available to us. Mythic is a bit of a challenge but that is still more of a gearing up dedication gear check difficulty overall.
The entirety of WoW's raiding content in 1.0 wasn't hard. But a few key fights were, and they made people work hard. The earliest being probably Onyxia. Between the hatchlings spawning and her tail whip and deep breaths, you really had to figure it out.
Molten Core was fairly easy as well. There were a few small learning curves, but you could readily get to Ragnaros without too much trouble. Learning him was difficult, though.
Also, figuring out the very first fight in Blackwing's Lair was pretty rough. Very steep learning curve, but the mechanics themselves were easy. The 2nd fight of BWL was a big gear check. Your DPS had to be substantial to beat Vael's death timer.
A lot of AQ40 was easy though. But a lot wasn't. The twin emps were incredibly difficult. Getting your raid force to understand swapping from one side to the other, while not pulling the emps together at the same time. Also, C'Thun was ruthless. You had to figure out the stomach phase, dealing with all of the tenticles, killing EVERYTHING, and still attacking C'Thun during the allotted time that he wasn't under a shell. This fight took so much practice. Viscidus was also a pretty big gear check. He was rough.
Then you get into Naxxramus. Every wing was hard, but Patchwerk was hands down the largest gear check to date. You HAD to clear as much of the other wings as possible before even attempting him. If your warriors weren't in 4 piece t3, good luck.
Thaddius killed SO MANY people. They were too stupid to swap sides. 4 Horsemen were rough. Loatheb was was hard, but I think Heigan's "DDR" style run through the ooze was even harder for people to learn. Spider wing was kids shit.
Then you get to Sapphirion. Ouch, she was nasty. And Kel'Thuzad himself. Ugh. When it came to skill, WoW's raids had EQ beat hands down. YES, they eazy moded the shit out of everything. You all get trophies. But it WAS ruthless.