Why did medieval writers sometimes employ gender role reversals?

Back in the medieval times women weren't treated as equals, they were supposed to be beautiful and useful, they were to clean the household and cook the food while taking care of the children, the men were supposed to go out and hunt and work and make money doing so, in the kingdom the women were wenches mostly except the queen, the queen was respected, and the princess was respected swell but forced to marry whom ever her parents chose and they had to be a prince. The gender roles are their because everyone thought that women were useless and weak and only good for baring children, cooking, cleaning, and raising children, and they also thought that men were strong and equipped with the abilities to go and and be knights and fight for their kingdom and their lives, that is also why we have gender roles now, a lot of people still think women are good for all the same reason likewise with men, and so the writers would sometimes employ these gender roles in their stories to go along with how it worked back in the old times.