Wario would still be an auditionee for Team Rocket, Mario would be doing 5% per up tilt, the wonderful nerf Greninja jokes wouldn't exist, Rosalina would be absolutely broken, Sheik, Diddy and Sonic would somehow be even more braindead than they are now, Luigi would still be fun to play, the game would be short four characters, Mewtwo fans would still cry their sodium-infused tiers, and many more.
To sum it up in short, this game and community would be several times worse off, there'd be ****storms and salt waves aplenty, and in terms of game balance, it'd be Melee all over again. So yeah, I suppose "not good" just about covers it.