Originally Posted by
Hitei
You could solo the vast majority of non-instanced content in Vanilla/BC, and the parts you couldn't were frequently either skipped, or taken care of by a guild member or two, because finding randoms was a hassle.
On top of that, in Vanilla and BC other players were an obstacle. An annoyance. Having someone else in your questing area frequently devolved into "who can tag the mobs the quickest". In Legion I frequently end up working together with nearby players because shared tagging makes teaming up effective. I'm on a DPS and see a tank who's pulled a bunch but is killing things slowly, so I jump in and burn them all down quickly, or I'm on Disc and see someone pull a named elite for a world quest, so I toss out an atonement on them so they can tank it without worry and help kill it.
There is several times more cooperation out in the world between players in Legion than there ever was in early expansions or Vanilla. And unlike those past instances, it's dynamic and quick in wow, instead of you sitting in Honor Hold for 45 minutes trying to find people for the trinket quest, or trying to out-tag someone in the same mat farming spot as you.