I think Ultimate Good vs. Ultimate Evil is just a narrative device. It doesn’t mean anything. It’s overdone because it isn’t even explored. WHAT do stories really mean when they say something is evil? It’s a shorthand for something but what?
Generally it means: it intends to destroy and take away freedom and it is powerful enough to destroy and take away freedom from...us! And us is what is good. What is good?
That’s even more ill-defined. It’s everything that opposes that destructive force. It’s us. Us being able to live our lives like we feel we should be able to. What does THAT mean? In a story. Peace? A certain social hierarchy? According to certain values..?
Star Wars, Lord of the Rings, etc. etc.
it’s not boring to go to the root of good vs. evil and be like: what do we even mean by that in this specific context?
The only author who I think truly has given a satisfying and conclusive answer to this is Terry Pratchett. Once you start treating people like things...that’s evil. It covers a lot of moral ground.