Can someone tell me why the “Donner Cut” of Superman II is the “better” version? Yeah granted I didn’t see Lester’s version and I know it cuts out most of the slapstick… but having an ending which makes the entire movie entirely pointless (not to mention reusing the much maligned superpower from the first film) really sours the whole movie to me.
I don't think the consensus is that the Donner Cut is the "better" version.
I'm not sure how much of the history of the production you might be aware of, but the shortest possible version of the story is this -- SUPERMAN: THE MOVIE and SUPERMAN II both began filming simultaneously, with Donner shooting the entirety of THE MOVIE and about 60% of II before the producers asked him to focus on getting THE MOVIE's post-production finished... then they inexplicably fired him after THE MOVIE opened and brought in Lester to finish filming II.
One of the things that happened within all that was a reconception of SUPERMAN: THE MOVIE's ending. Originally, Superman didn't turn back time in that movie, and that was always intended to be the ending of II. But Donner and Tom Mankiewicz (the writer he worked most directly with) decided that the turning back the world concept was so good that they should use it at the end of the first movie, and then once they came back to finish filming II, they'd figure out some other ending for II.
But Donner was fired, so he never got the chance to work with Mankiewicz to figure out a new ending for "his" version of II. When he was approached about putting the Donner Cut together, his options were to either use the ending of the Lester theatrical cut (which Donner didn't like and had no hand in) or go back to the very first idea for II's ending (turning back time), even though they'd already done that at the end of THE MOVIE.
To me, the Donner Cut is a curiosity, but not really a "real" movie. There are too many compromises and rough edges. But there are things I like in it more than the Lester cut (using all the Marlon Brando footage, using more scenes that Donner shot but Lester removed/reshot).