Back when I played adventure/RPG games...the one thing that broke me out of the suspension of disbelief in most games was how, after defeating an enemy who was clearly using some amazing equipment, your party wouldn't bother picking it up and instead, pick up a few GP and maybe a "Short Sword"
Of course, I realize now that that was a reasonable constraint of game design and balance. So it's not coincidental that my favorite RPG of all time, Ultima 7, had a famously in-depth inventory system, and yet also was so unbalanced that combat was mostly pointless.
Halo 1 actually does that. The Covenant Elites have neregy swords that dissipate once you kill them, and the grunts had plasma cannons that would just explode when the grunt was killed. That's why it was so epic when they made those weapons pick-able in Halo 2
(And Tartarus's Gravity Hammer in Halo 3!!)
Still waiting to be able to pick up Hunter's built-in arm weapons though....
Of course, I realize now that that was a reasonable constraint of game design and balance. So it's not coincidental that my favorite RPG of all time, Ultima 7, had a famously in-depth inventory system, and yet also was so unbalanced that combat was mostly pointless.