I don't understand how this is exclusively a men's issue. Now this is completely out of my realm as a gay woman but wouldn't this roughly mean that there is a similar amount of straight women who are single as well? In my experience polyamory among the straights isn't nearly as common as the internet likes to make it sound. In general, millennials (and I assume gen-z as well) are having less sex on average and getting into less relationships than previous generations.