Historically, it has (to my knowledge) always been the elites and upper classes (not to be confused with the "upper class" "celebrities" of today) who have done the polygaming. They could take on and care for their many women, and they had the auctoritas to do so. Granted, the lives of said women were not always most enjoyable, but then again, neither was the life of an average man or woman in general. But in on big regard the women had it better. They could be subimmisve and feminine, and rely on a masculine man who did not cater for the whims of the women. Any weak man, especially a king, would have been killed off pretty quickly.
Even today most feminine women would likely prefer a masculine man who has many girls around, than to be forced to become a masculine woman and take care of a *****.