Well in fairness, rotj palp did have a decade plus to grow, and luke was a newbie to the idea of tutaminis and didn't have a lightsaber to block the lightning.
But Yoda's holding a living mountain in place while massively hindered is the most powerful force user all time up until Sidious, and is as of rots virtually tied with the best duelist and force user in galactic history.
ROTJ Luke is still losing
edit: In canon, luke never actually used tutaminis
Vader's absolutely inferior to Anakin in pre-Disney Canon or Legends. It's possible he's better in the new Canon (time will tell), but I'd wager he isn't, since the core theme of Vader is that he lost everything - not "lost everything (besides his Force power (which really made him unique in the first place) - despite now being more machine and, as a result, would have a weakened connection to the Force)."