Polygamy? Or Monogamy?

Im watching this show called “Sister Wives” and I started thinking why does a guy need 4 wives? Why is a woman ok with sharing one guy? Is this just a license to cheat for him but the women need to stay monogamous to only him, that doesn’t make sense to me, it’s like saying “here for the rest of your life you get steak…no other choices forget it, but I will eat buffet nightly!” Is a guy that great? What’s your choice? And whatever your choice why not the latter?