It’s an interesting question. In a way calling something ‘evil’ is an exaggeration, nothing in nature is truly wicked or irredeemable. It sets you up for a fight, it tells you here is something you must defend yourself from. Good too is a caricature, very few people truly have your interests at heart, almost everybody has his own agenda. To see the world in caricatures prevents you from seeing the true motivations of humans and animals.
Still there are human impulses which are deeply unbeneficial, such as cruelty, anger or ruthlessness. These are things one should guard against because they can block out one’s heart feelings, to as the saying goes ‘harden one’s heart against mercy or pity’. Whereas in fact our true nature is to live in compassion and love.
I find it a pity that the sense of irredeemable wickedness has grown to be so popular. Movies such as those after Stephen King’s stories, or something like The Ring, or even series such as Good Omens provide numerous examples. It’s a cheap tactic to cast the villain as being an embodiment of evil, while in fact the vast majority are only exceedingly greedy.