>The emphasis I would hope would also be for improved negotiation tactics, better resource sharing and goal alignment between groups of people.

The fallacy in the line of thinking that "why don't we all just shake hands, say something nice, and get along with each other" comes from the erroneous belief that everyone in the world just wants peace and material prosperity for themselves and their people. This isn't the case, for countless reasons.

Peace is what you and I want, because we're living in highly privileged lives where maintaining the peaceful status quo (one in which we're on top) for as long as we live is the best outcome for us, and because we have a fairly rational view of life and the world (e.g. we are not convinced that killing a certain people is the only key to an eternity in "heaven", or have bought into some myth of ethnoracial/cultural exceptionalism that needs to be defended by any means). We also aren't emburdened by some great injustice for which we have a burning itch for vengeance (e.g. no one has bombed your whole family).

This just isn't the case for everyone in the world.