Yuyu's attack at AW80 is 535. Adele's at AW 90 is 517. Yuyu is also cheaper. She loses in HP, Defense, Attack during skill (her skill buffs range instead) and doesn't get the Team HP Up AW buff, but is superior for what witches are supposed to do: Be an early magic unit that does good damage and slows enemies. She gets press for Wall of Magic because her attack is superior to platinum witches while being cheaper and having the Range Up skill necessary to catch that one wolf that tends to get away from Adele/Despara. Being Gold rarity also means she's easier to min-cost than the plat Adele or Black Despara, further cementing her cost advantage (AW gives Cost -1)