Eve was lured by the serpent’s lie the Tree would bring her happiness, which she already possessed - being tricked she traded that for pleasure-pain outside God’s perfect will.
The serpent offered them the chance to be "as God" knowing good and evil. There is a big distinction between being "as God" (functionally the same) and being "like God" (created in His image).
This is original sin. The desire to be the one who decides what is good and what is evil for ourselves apart from God's word. We are not capable.
This is at the root of the attempt to normalize all of the evil we see today. Transgenderism, homosexuality, pedophilia, all of the evils of the deep state. They aren't satisfied to practice evil and get away with it, they insist that you agree that there is nothing wrong with it. The "knowledge" of good and evil. Usurping the prerogative of the creator.