All I remember before LFD is ppl whispering me 24/7 to tank for them. Not sure that made me feel like I was playing an "MMO RPG".
We raided 10m and 25m so that was the closest to MMO, not the dungeon experience.
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I remember in Wrath, later on, ppl jumped at gear score because it was an efficient way to judge you and make things fast. You can be social if you want, you won't be social if you don't want.
M+ is living proof of this on retail. Ppl have to make their own groups. But how many ppl befriend others after a run? Almost nobody wants that and I myself don't understand why. Those who do, do, no matter the tools.