As much as it doesn't really feel like it, items are one of the most important parts of most games. Between finding perfect equipment or weapons for your characters, or merely finding all the collectibles to net rewards and trophies, a lot of your playing experiences revolve around getting the items that you crave.
Only, not every item can be the thing that you needed, or the process becomes way too easy. You need some duds and red herrings added into the mix to make things more interesting - and to provide you with the sense of frustration that makes getting what you were after all the more satisfying.
But it can be surprisingly difficult trying to figure out what is actually useless, and what is a useful item that you merely haven't found the use of yet.
Some of these items had players spending countless hours of their lives trying to figure out their purpose, only to have it revealed that there wasn't one in the first place. Inversely, some of them are transparently useless items - that people still somehow bought.