I'm usually frustrated by these kinds of debates — individuals never get a chance to go into much depth because their time is so short, and I want to hear counters to the better points raised before they are dropped for lack of time.
But I thought a 2:2 was a large improvement over a 3:3 (which is what most debates in the past I'd seen). I didn't mind it. There was some depth.
I think for a general (non-less-wrong) audience, a 1:1 debate can have a trap that it's perceived more about the individuals and their personalities than the issue itself. A 2:2 feels (to me) like it keeps the issue in focus significantly more in perception than the people talking. Or at least, there's lower risk that an entire movement is viewed under one personality. I could be wrong.
In theatre I've seen this with 2-person scenes vs 4-person scenes. The 2-person scene is typically significantly more than double in potential for intimacy and feeling.
For instance, I am thinking about the munk debates which in 2023 tackled AI x-risk. I don't see how adding more people to a 1v1 debate makes it better in any way. One of the major frustrations with debates is that it is difficult to get the participants to respond to each other. The goal would be to have the participant with the better claim manage to pin down where the weaker argument is incorrect or relies on a false assumption. But with more people added there are more opinions and confusion along with less direct responses. My question also refers to other debate formats with more than 2 participants.