Is there any retro consoles that you never lived up to their potential? where the games fell short of the hardware?.
Personally I feel that the NDS was under-utilized, as it was a fully 3d capable console, that was used mostly for 2d pixel art games, and platformers. When it was able to support full 3d platformers and even a fan remake of portal.
The Wii U tried to bring the DS to console, but there was one major limitation that kept it from being used the way the DS was: human eyes cannot focus on screens at different distances from the eyes. The DS only worked because both screens were right next to each other.
The one thing the Gamepad could do that worked quite well and deserved to be explored more was asymmetric multiplayer. But at the same time, it felt like it was an era too late to be a big deal - giving players separate screens is something we can already do via online multiplayer.