@Kaarme That's a good point; I was thinking more of the absolutely
endless fetch quests you get in MMOs: "Hey, brave hero who could smite me where I stand with a sneeze, can you take this love letter to the busty chick three doors down from me even though I could totally take it myself? I'll give you five bucks!" or the inane quests you get from the positively appallingly written child characters (looking at you, Bethesda).
But that would make for an interesting character, for sure, if their compulsion to clear
all the quests resulted in them taking on the morally dubious ones... To say nothing of the ones that directly conflict with one another (like "Protect the King from Assassins!" vs "Assassinate the King!"). Or things you can't do in a single new game cycle (like the Twin Princes Greatsword from Dark Souls 3, for an example off the top of my head, where you have to be minimum NG+ to make it).