>>54925013Eh. As more pokemon are added, more metas are "needed" to keep the same idea that most pokemon have a place in at least one meta. OU can only realistically hold around 50 Pokemon, and most tiers follow suit for how many pokemon are in there. Hence, we started with just Uber, OU, and UU, and now we have RU, NU, PU, and ZU.
UU Ubers is an extension of that, just in reverse. Too much stuff is starting to get banned from OU, so much so that now theres a glut of pokemon that are in Ubers, but really feel like they've been removed from the game entirely.