Not every game was succesful on Nintendo DS and 3DS, but some games completely failed. Reddit User HxCurt is working for a recycling company and he shared a photo of a box of handheld games that nobody wanted.
More than a half ton of games and their only value is now as scrap. He writes that most of the games are iCarly 2 - a game for the teen soap on Nickelodeon. But there also other games like Wreck-It Ralph, The Amazing Spider-Man and Dreamworks Super Star Kartz. So yes, we guess it's all junk.