Children whose disagreement is consistently shut down ('because I said so', 'don't talk back') learn to suppress their actual views. The pattern produces adults who can't hold their own opinions or push back against authority.
What allowing disagreement looks like
Hear them out. Take their reasoning seriously. Explain your reasoning. Sometimes change your decision based on their argument. Sometimes maintain it with explanation. Not all decisions are negotiable; some are.
Children of disagreement-tolerant homes grow into adults with stronger sense of self. Worth the daily friction of letting them push back.