Opinions, opinions....
But the undeniable fact is that a shitton of W3-s side-missions, including the world, were basically handcrafted in high detail and all the characters, even for the most tiny side-quests were fleshed out perfectly. Including the perfect audio, the perfect facial expressions. The story itself branches so much and each branch feels unique. It didnt have any lameass fetch quests. Majority of the quests were pretty fresh and unique. That my friend is a veeeeery high bar. Considering that TES-s world for example was basically just copypasting and bunch of fetch quests.
Dont get me wrong, I can totally see how someone might find W3 boring, but you cant deny it its strenghts. After W3, im quite sure developing side-quests and characters properly is going to be a norm from now on in RPGs. Its inpact on the genre was definately heavy.