I think you're right that Pairagraph in its present form probably won't be 'the last word' on a given subject. That may be a point in favor of expanding the format and allowing >2 people per dialogue.
I might point out fivethirtyeight's live blog as an example of how this can go wrong[1] - there is an unpredictability to discussion here which is partially covered by the fact that they are responding to live updates but suffers from the fact that discussion threads will suddenly die off.
1. One random example: https://fivethirtyeight.com/live-blog/biden-inauguration/
Thanks for the link for an example of how not to do it!