I think you can say the same about most professions that are "big picture" ("individual picture" professions meaning teachers, doctors, EMS; folks that help individuals rather than larger trends).

The reason here is similar to why science oftentimes appears fundamentally worthless - most of the time you uncover absolutely nothing of importance. I think the same is true for data organizations. When you're looking for large patterns in the data you're going to strike out a lot. And that's not on an individual level, but on an org level - a lot of teams within the broader data organization will never produce anything of value. But at least they'll try.

With respect to data quality - fix it then! That seems like an immediate way to make your work less "fundamentally worthless". I understand that fixing data quality is hard (I spent >12 months working on that problem at my current company), but it is not a worthless endeavor.