Nobody (I mean, nobody) likes to acknowledge it, but some of the most extreme second-wave feminists like Andrea Dworkin were calling out the dynamic you see in r/polyamory in its previous iteration. “Free love” was used by older men in the 60s and 70s as a way to pressure women into uncomfortable relationships, lest they seem insufficiently radical. The only thing that was really “free” was the men seeking to be “free” of consequence, disappearing when they knocked someone up or passed on the clap. In my opinion, you still see the worst of this manipulative stuff with the men trying to pressure women into being woke and miserable.
Honestly, the least-suspect version of this poly stuff is when it’s being done by LGBT people among themselves. They’ve usually done some homework.