I can read Japanese but I can't speak it very well but I will try to explain the usage of "or" and "and"in this sentence. Using "or" means that the only choices available are "可愛い“ and "かっこいい.“ Using "and" may hint at the meaning that there are more choices than just "可愛い“ and "かっこいい“. Such as “怖い“ とかね。 So if the meaning of the sentence is that "it is unfair that everything is ONLY cute or cool." Then the usage of "or" would be correct in this case :) I'm a Hong Kong born Naturalized citizen of United States of America who minored in literature and writing. I learned Japanese through college classes, watching a lot of anime and dramas, and also from doing 生放送 on niconico in the past. I might not be entirely correct with the understanding of "or" and "and" but this is how I understand it. If I'm incorrect, please correct me so I can learn too! 😊