The Devil's Advocate
Call me Dad
i mean they didn't show this "greater power than master yoda" in the first 3 anyway... dude lost head up to obi won...I don't know how, it seemed clear that Vader was a shell of his actual power. He looked like a defeated, decrepit old man in RotJ, and that should've been enough indication. Episode 3 Vader was the strongest Jedi of all of the films
then in 4, he beats obi straight up, in 6 he kills the emperor, in 5 he beats a young luke head up... i mean i see he was SLOWER.. but less powerful really doesn't come off until dude said so above.... that was never alluded to in the movies... if anything, they didn't even have the backstory of him being most powerful and losing power until the prequels... so why would they know to show that in 4-6