On a personal self serving note. What attracts me to it is the ability to rapidly build wealth and a larger family. The simple fact is I need more help to expand my empire. I could double my income next year with a halfway competent person who's totally invested in helping me be successful. A couple more people with varying skillsets would quadruple income potential. I could establish a firm and resilient financial future for my family to great grandchildren in scope. Monogamous, I can benefit my grandchildren and set my sons up well, but it makes me giddy thinking of what I could accomplish if I had 2 more Caties helping me, just boggles the mind. I understand why it's illegal, the power families would retain would terrify the oligarchs in power. They would no longer have power.
It sounds so fun to have a larger family and some friends closer than a sister for my wife. I get so much joy from seeing her interact with her sister, joke around, share their stories and laugh together. It would make me grin ear to ear to have even just one friend like that sharing her life every day. I'm great, don't get me wrong, but she is different with women and I know for a fact that she would blossom under that type of situation.
(and before anybody suggests it, her sister is married)