We've still found that the only women generally available have major drama and baggage. Maybe we're going about it wrong. IDK.
Women for the last 1700 years have grown up in a monogamy focused world. Most of them have never thought of plural marriage as an option, or realized that it makes no sense to look for a marriage minded man among those who remain uncommitted.
Most too are not exactly reasonable about what they want (are looking for). Like my hubby's niece who "Would never share "her" man" yet got into a relationship with a man who already had children with two other women. He also abused himself with substances. She left him (divorced) hoping he would get clean....sadly, he commited suicide instead. Now she is looking for a "family man" among the single men. One who will be OK raising their daughter....but who doesn't want children of his own.
Our first child was quite stubborn about some ideas. He didn't want to share my popsicle. If I offered him.a bite while I was holding it, he would refuse. If I got down the the last bite on the stick, and then gave it to him, actually put it in his hand, he would happily eat it.
Some women are that kind of stubborn. They might marry the man in 20 years after his current wife dies, but don't want to touch him while she's still touching his heart.
Then too, many women have not seen healthy marriages....even monogamous ones. They have no clue that it's possible to add someone to that mythical "happily ever after" without destroying it. I wanted a sisterwife. I had other people afraid that it would mess us up (mess up our happy monogamy) to add another woman to the family. I'm fairly sure his family and hers don't expect it to last.
Baggage? That is probably part of why those women are open to polygyny. They need help and support, and aren't getting it from the party animal they had their kids with.
It's just a bit like those birds that lay their eggs in the nest of other birds. The egg layers don't raise their own young....they fly off with not a care in the world. The other birds who's eggs were pushed out of the nest invest their lives into raising young of another species. My brother in law married a woman with two boys. They also had three together. She left him after he was disabled....even though he was still providing for the family.
You and your wife now have a different idea of how family life could be, but many will not be able to see that vision. What you can see you comprehend from that position of love and stability that is your current reality,... but some have never known that kind of love.
There may be someone with a ticket to your destination....who just hasn't arrived yet. Time will tell.