What caused the decline of EQ as the #1 MMO?

[Messianic]

WoW was a natural next-progression in MMOs. At the time, it was leaps and bounds ahead in overall game design, be it the way classes, talent trees, and abilities were structured, or having an already established set of lore to build on, or graphics (at the time), or the functionality of the client...

In every way, WoW was everything an MMO needed to be (at least for most US players) for its first few years - that's why it was so freaking dominant in the states for so long. It had balance issues, yes, but it had done better in that area than any predecessor.

Everything about it was so polished - the raid content (Running UBRS the first 10 times was fun, it did get monotonous after that though), instancing, the variance of strategy for large raid bosses...

Even the lower level instances were so much freaking fun to run. Each class could be dramatically different depending on how you specced (although in PvE you were usually pigeonholed). Pure mob exp grinding wasn't the route to 60 - questing and instancing were.

I'm not idealizing it, I'm just pointing out the pros WoW had in its time.

The whole MMO genre changed a lot over time - and WoW was able to actually predict where the market was going and fill nearly every single desire most MMO players wanted. It was a pretty impressive piece of work.