>>31321629I could thing of a few reasons.
1: 4x stealth rock weakness
2: Tapu Koko/Xurkitree
3: Gigalith, and Pelliper being good weather setters to counter Char Y
4: it's frailness physically is a real problem as this meta gave us alot of good new physical attackers. Goodra, Primarina, Gardevoir also suffer from this and are probably doomed to UU for this gen.