It's interesting that you posted this as a history question. I'll offer a bit of history in my answer.
As a conflict resolution strategy, using "I" statements can be helpful to calm and diffuse anger. If you came to me screaming about how Brainly wasn't answering your questions the way you wanted, I could say something like, "I can tell you are frustrated. I know I get frustrated when things aren't happening the way I want them to happen. Can you tell me more about what you were wishing were different in this situation?"
The idea of identifying with our fellow human beings and hearing them as individual persons was explained wonderfully well by Jewish philosopher Martin Buber. His famous book "Ich and Du" (published in German in 1923), or "I and Thou" in English (translation published 1937) proposed that we too often treat other human beings as "its" -- as scapegoats or representatives of a thing or group. We want to treat one another always as me and you, as persons, as human beings who have inherent value as human beings. Doing so in a situation of anger or conflict is especially important as a way to manage that conflict.
