I haven't known this kind of competition even existed. But it strikes me as weird. Why does it even exist? Training kids to win a debate? What is that good for

I haven't known this kind of competition even existed. But it strikes me as weird. Why does it even exist? Training kids to win a debate? What is that good for? If we want them to exercise debate as a democratic institution shouldn't we rather focus on ability to understand the opponent, to change one's mind, to reach compromise? One way to make that competitive would be to deliberately build a prisoner's dilemma into the rules: If one party wins, they get the most points. If they reach a compromise each party gets some points. If either party fails to convince the judge, nobody gets nothing.