My root comment on this subject was made in the context of the OP comparing verbal vs written conversation. To be clear, I don't disagree with your main point and in fact, I've made the same argument.

I do lean towards disagreement on the idea that it "wouldn't change much" (of course, defining that phrase is problematic), as it seems to me that a large part of "winners" and "losers" in debates is "mere" presentation and likability in that format and that these presentation and likability skills mean little towards the effectiveness of fulfilling their purported jobs. Reference the classic example of the Nixon/Kennedy televised debate (a quickly-googled link for a refresher).

In a written format presentation and likability are also important but candidates can have all the help they need with as much time as they need in a written format.

In all, though, I don't think we disagree much on this. I, too, would like more rigorous debate moderation and if I had to choose between written debates with current standards of debate moderation and verbal debates with rigorous moderation, I'd choose verbal debates with rigorous moderation.