They're by no means equally compelling. But they are viable ways to generate currency, you progress in them over time as a specialist, they feed back into the player economy performing tasks that other people want performed, and they are, importantly, in the same world, on the same shard. I know not to go near Orc Camp because there's a group of player killers down there, despite the fact that there's a rich Agapite vein running through the mountains near the entrance that I would love to mine and make armor out of. Back to the relative safety of Minoc for me, however crowded. In some timeline two weeks in the future, I band together with a bunch of other players (most of whom just want to farm orcs) to kick them out. Territorial control, even without any formal mechanics of territorial control, is closely correlated with narrative and socialization; I wouldn't have met any of those players if we were all on our own separate instance.

Eve Online accomplished something a little more combat-focused, but similarly diverse in playstyle, mostly by dint of having a single large persistent world-shard with minimal functional instancing.

> having a single large persistent world-shard with minimal functional instancing

What do you mean by this?