There is a specific silence that follows a won argument. You have the better evidence, you produced the dates, the other person has stopped talking — and the room is worse than it was before you started.
Being right is easy to verify and cheap to collect. Being kind sometimes means holding a correct fact in your mouth and never saying it, which nobody witnesses and nobody credits. Most people can name a relationship that would still exist if someone had swallowed one true remark at the right moment.