I think that Eureka (and Diadem before it, and FATE grinding before that) shows a fundamental problem with FFXIV: outside of raids, the combat isn't fun. Monster Hunter for example is incredibly grindy, but the combat is intrinsically fun and satisfying, at least for the first 20 hours or so.

Now, I'm not expecting any revamps to the combat or anything like that, but improving Eureka means diversifying the range of activities and not just putting a microscope on the fact that FFXIV's combat is boring. Like delivering supplies to camps or other settlements, or defending bases, maybe crafting usable turrets or something