And we can assume the user of Clamperl doesn't predict correctly 100% of the time. Easily outstalled by anyone who knows what prediction is.
So is Garchomp, Lucario, and Salamence. Everyone can predict 100% of the time, and there is no way your opponent will either guess right or reduce themselves to random moves.
Oh wait, prediction is glorified guessing? huh.
You only have a real advantage in prediction if your opponent is less skilled.