Using the most barebones definition, items in the Legend of Zelda series are necessary for progression, usually being required to complete dungeons and specific puzzles. These items are then carried out of the recently defeated dungeon and into the world, ready for other secret-finding purposes, or simply to expand the accessibility of Hyrule or other locales.
However, there are certain items that are rendered useless after their discovery and initial use, contributing nothing to post-dungeon discoveries or uses. Not all of the useless items in the Zelda games come from dungeons, however. Some of these require mini-quests, or are even just found lying around.
These one-shot items have found their way into the more extensive Zelda games, limiting themselves to the 3D world of Zelda. In fact, it is even noted that items that were deemed useless in the 3D games got upgraded in latter top-down Zelda games, making them more worthwhile.
5. The Slingshot - Twilight Princess
The Slingshot is a staple of ‘Zelda’ games. Attaining the slingshot in a ‘Zelda’ game opens up Link's ability to defend himself as well as get through certain puzzles. In other 'Zelda' games, the Slingshot continues to aid Link throughout his adventure after he initially recieves it.
Twilight Princess does away with this, however, as the Slingshot gets replaced a couple dungeons after receiving it by the far superior Hero’s Bow. The Hero’s Bow not only shoots further than the Slingshot but also has a higher damage output. There’s something to be said about Link’s age while using the Slingshot. If Link uses the Slingshot as a child, it’s one of the best weapons in his arsenal.
However, if Link uses the Slingshot as an adult, like in Twilight Princess, he’s essentially fighting world-ending monsters with a children’s toy.