I think the armor progression in this game is really weird, at least before G-rank. This is not about the very grindy (MMO-ish) drops that mar an otherwise brilliant game, but that plays a part.
Since getting into High Rank I've had like dozens of armor sets pop up all at once (like a new one or two every mission) on top of the ones that just showed up for the highest rank of low (e.g. Lagiacrus, which I'm still wearing now just hit G-Rank, although at least upgraded to be 40 defense a piece). Less than three days later I've hit G-Rank and now they are mostly outdated at this point. Making even one of these sets (or a bunch of decorations, in some cases) can be daunting, with one or two super rare drops required. People generally seem to care more about ranking up (doing the three or so key quests) than fighting all of the monsters or fully equipping themselves with proper skills, but I can't blame because the game is set up this way.
The rate of obtaining a full set of armor (skills) versus the rate of them being outdated is so out of whack it is mind boggling. All throughout High rank I was confused what to make because of this, but never even got an opportunity to make a set because I never got a full set of materials (for example I killed somewhere around 8 Uragaans). This doesn't fully apply to weapons because you upgrade those along and they alone require much fewer materials. Still though, it was far easier to make an up to date Dios blade than go back and continuing upgrading my Peco Switch-Axe.
Anyway, I think I'm going to focus on more High Rank missions for awhile.