Debate is broadly a useless social ritual, but I’m really skeptical of the statistic she trots out near the start. I think even if you don’t change someone’s mind outright, you can nudge them in the right direction, and someone who changes their mind that quickly within a discussion has probably already received a lot of nudging (albeit mostly not from debate).

And this is different from public debate, which can only possibly be used as an advertising platform and even then should only be done after careful consideration of the possible outcomes.