I've never played World of Warcraft

[WarpathEQ]

Also never played WoW but as I recall it the timing of events was really the main draw. While EQ wasn't the first it was by far the largest MMO of its time with a relatively massive player base dedicating countless hours of their life over several years.

Then in quick succession you had both EQ2 and WoW dropping in November of 2004. At that point given the massive multiplayer component and its importance in this style of gameplay players were left with a choice...

1) Stick to existing EQ but take a huge step back due to server attrition and lose a bunch of people you enjoy playing with. There was largely an expectation that all dev work would migrate to EQ2 and that EQ would be left to die.
2) Start fresh on EQ2 which didn't really seem to have anything new or exciting to draw players into it was basically viewed as a new expansion except you lose your characters and gear.
3) Try WoW which was a completely different scratch built MMO, it was built off the beloved warcraft franchise which most people that were into EQ enjoyed, and its more cartoonish look had even more mass appeal to less hardcore gamers or casuals.

Sitting on the sidelines looking at your options WoW was a clear winner as it just had more mass appeal for a larger player base and from there the rest followed. I choose the uncommon option 4 of walking away from MMOs altogether for 20 years