Luck (Rare Drop Rate) is Garbage?

I’ll start with my Guardian Rank. Luck is currently +8.43. Now combined with items like the Loot Expanding Static Charge, which gives me another +12.67, for a total of +21.10%.
While I have P.U.G.ed up with buddies or others while farming I hear that sweet, sweet “tching” come through my headset on them having found a legendary, while they have a lower percentage rate than I, while I come out empty handed or set offline (like a LOT OF PEOPLE recommend anymore, which to me, sorta takes the fun out of this game, as i like to P.U.) Now, not only have they had better luck than I, they also come across a lot more rare items which makes me think that the whole percentage rate matter is useless.
May I get some input on this matter? It is really starting to stir me and i would like to know if its just me…