Well, I don’t think ROTJ makes a great argument for Vader’s redemption, either (and that’s partially why the Prequels are so hamstrung, because they’re primarily interested in retroactively centering Anakin so as to make that by-that-point foregone ROTJ victory HIS, and not Luke’s.) but Vader’s “redemption” isn’t really about Vader at all - it’s Luke’s reward, not Anakin’s. Vader’s redemption is representative of Luke’s faith in himself, and in the Force. Knowledge and defense. Love and compassion. Those are the things he believed in, and his reward for that belief was finally getting to REALLY meet his father for the first (and last) time. The redemption’s purpose isn’t to reward Anakin’s character. It’s to reward LUKE’S. It’s an affirmation of the Jedi way. Basically, Vader’s redemption is a byproduct of Luke’s arc completing successfully, and that moment’s resonance hits so hard because it’s a reflection of how well Luke’s story concluded.
Reframing that moment so that it’s a referendum on Anakin, and then going back to tell Anakin’s story as a means to justify that reframing is basically the exact place that Lucas lost control of Star Wars from a storytelling perspective, and it’s arguable that he never really got it back, either.
(that his attempt to re-frame it was as confused and awkward as it ended up being didn’t help, either).