In my opinion, the second film was stronger than the first. And the main reason was the more or less adequate villain. Gene Hackman in the first film reminded a lot of Dr. Evil from 'Austin Powers', so it was impossible to take him seriously (even if the parody with Meyers was made 20 years later, it does not change the essence). The beginning of the second part did not bode well either... Terrorists with a hydrogen bomb - that's something!
But Terence Stump came along and saved the day. General Zod may be a typical tyrant who wants to rule the world, but it's only at this point that you realize this was the villain the first part was missing.
With Stump and Hackman's clowning in the background, Lex Luthor getting rid of Otis was just the soul of the movie. His humor is spot on in this movie (his dialogue with Superman at the end was especially satisfying).
As for the main characters, Christopher Reeve and Margot Kidder played at the level of the first part, so those who liked them in the first 'Superman' will not be disappointed.
All in all, at the second attempt, they made the 'Superman' they needed. Yes, there are flaws (I don't want to remember the beginning of the film), but on the whole it is very good.