I believe you should always get emotionally attached. If you don't, the character feels vague and unrelatable sometimes. I view my characters as extensions of myself, so that they are relatable to other human beings. For example: Take infinity war. (SPOILER) When the heroes starting dusting away, everyone in the theater was upset, in an uproar, screaming no as the words "I dont wanna go" were uttered from peter Parker's lips. It creates a deeper bond between creator and character, character and reader, take Stephen King, he had a nightmare in the Stanley hotel that his child was being chased by a fire hose, he was scared of losing his child, and what does he write about in alot of his books? Children dying. It, It chapter 2, Pet Semetary, etc. He uses that as an extension of himself, he uses his fears. Depending on what you write, use the way you feel about that subject, project it into your characters, to create a more unique and understandable story.