Mistwell
Crusty Old Meatwad
The issue with stacking almost everything on sneak attack is you're able to get it most rounds, but not all rounds. And the higher the level, the more unusual circumstances which disallow sneak attack in a particular round, often due to sight issues and disadvantage.If you want to improve your Rogue's damage, an item that grants Sneak Attack damage does make more sense.
For one, the Rogue is already the party member who will be seeking the situations that allow sneak attack, and will often have subclass abilities that enable it in more situations. Making the items Rogue only is probably unnecessary.
For two, the suggested items that deal extra 2d6 of poison or piercing damage are probably going to be given to a class for which they are more effective: one with Extra Attack, like a Martial or Bladesinger. Unless you are going to add Sneak-Attack-like restrictions to those items, dealing +2d6 twice (or more) each round is better than only dealing it once.
Just giving them a different kind of extra damage would help with this. Poison seems to be the new focus of this version of the rogue, and it makes sense.