There's a bit more to it than that. Identifying with my ideas makes challenging them stressful, yes, but debate changes a potential eustress into distress. A dialectic where we're trying to leverage different initial perspectives to both arrive at a better understanding of the truth feel like I'm risking something valuable to win something more valuable. It's stressful but exhilarating. A debate just feels like I'm protecting something of value from someone who brings nothing of value to the interaction. Because I assign value to ideas, debate feels inherently destructive and negative-sum.