I broke my circle pad because of Smash 3DS, the poor thing just wasn't made to play Smash, or at least not by someone who had been playing the game on Gamecube Controllers for over a decade.
I feel Smash 3DS is one of the reasons that Smash 4 lacked a clear vision in comparison to the other games in the series, they had to make a lot of compromises because of it (gameplay being the worst one imo), and the connection between the 3DS and Wii U versions was never really fully realized into what it was initially built up to be, I feel like they had some idea there that just didn't happen for one reason or another. It's nice that the game could sell well despite the Wii U flopping hard, but it does feel like Ultimate is coming in to properly utilize all the work that was done on those games, because right from the start Smash 4 felt like it was almost there, but not quite.