Why do kids blame themselves when their parents fight? #trauma

question is why why do kids get so attached to that story why do they take it on as if it's their problem so it it comes from a place of loving the parents so much and as I said I I can't see the painful truth as the truth which is that it's not my responsibility and it's fully their responsibility because that wouldn't make sense to me then why are you fighting if it's nothing about me so there must be something wrong with me and I don't even why but but why why is the but why is there the mechanism