Vader’s redemption kind of comes out of nowhere. But it doesn’t matter unless you expect a fully realised villain, with many facets and deep characterisation. The Empire might seem like fascist super state, but meaningful comparisons to real historical figures are not really appropriate. It’s just Star Wars.
All the more reason why Trek is the superior Star franchise.
Maybe once, not so much these days.
Difference is modern Trek doesn’t retroactively ruin what came before. At least not for me.
Have you seen the new Picard show?