Well power imbalance as in polygamy as well as monogamy mindset whilst engaging with other people can make this not work. In my opinion “wife swapping “ tends to fit into that category. In true ethical non- monogamy you wouldn’t need to leave one partner to take up with another one.
I think that any kind of hook -up culture will see a lot of pain and dysfunction but that’s not what real poly is. It’s about connecting on whatever level you do, which might Even be only minimally sexual, and then co-creating partnership-oriented relationships.
Right now we are on vacation at a clothing optional resort and one of the staff told us that “ lifestyle” people are the nicest, realest people she’s ever met. I think this is in part because they tend to be emotionally more mature, although not always of course, but they are also authentic because they are actively making a choice to go against the grain and to choose what’s right for them despite what society deems appropriate.
Again it’s not perfect in every instance in part because we don’t live in a world that currently supports this, but pre-agriculture everyone lived that way. They lived in partnership oriented groups that found sexuality to be a way to connect with not only their own divinity but also to connect to the Divine. You have no doubt heard of the (erroneous) term temple prostitute. This was a way to connect to the Goddess via her proxies, to heal from the traumas of war, etc., to “marry” spiritual power and temporal power as in the heiros gamos. And much of that survived well into the time of agriculture- until about 5 thousand years ago.
But we live in a deeply misogynistic, deeply non-spiritual dominance hierarchy that enforces monogamy largely as a method of control. If couples want to choose that freely, they should but most people don’t realize they have any other choice.