An underappreciated feature of nonmonogamy is that it makes ethical conflicts of interest a bit more challenging. This article doesn't discuss that explicitly, but does hint at it in some of the quotes
Look at how few people can even agree what open/enm/poly even means in this discussion.
Then add more parties with more emotions and more abilities to act out…. More degrees of freedom means harder to predict.
And then also add in that Society is going to have an even harder time holding anyone accountable for anything in these kinds of situations - he said/she said is hard enough, what about when it’s he said/she said/he said/she said/they said?
Just give up and throw everyone in jail? Or no one?