I think historically, most of the gain of increasing cooperation has occurred not by opposing tribalism, but rather by channeling it in broadly socially-useful directions. Democrats and Republicans might not kill each other, but that’s not because they aren’t “tribes” of some sort. Indeed, it’s not clear how politics itself could even work absent some degree of ‘tribalism’ (which should rather be called factionalism, but never mind that) as a basic organizing principle.
I think historically, most of the gain of increasing cooperation has occurred not by opposing tribalism, but rather by channeling it in broadly socially-useful directions. Democrats and Republicans might not kill each other, but that’s not because they aren’t “tribes” of some sort. Indeed, it’s not clear how politics itself could even work absent some degree of ‘tribalism’ (which should rather be called factionalism, but never mind that) as a basic organizing principle.