That's what I call a waste of time, and I use databases precisely to avoid that. "Oh, turns out I spent hours pursuing an objective that was bugged/didn't actually exist ! Those sure were well spent hours !"
Knowing where such and such item drop allows for planning if you prefer an organised experience.
Different story for some things where I find part of the pleasure lies in the search. I'll never use things like NPCScan, for instance. It goes without saying, but YMMV.