In the past there was also the issue of what was being done in the conjugal bed. There were things that men would not have done with their wives (let us take the Victorian stereotype) - the conjugal bed was for respectful procreation and prostitutes for the rest. To the extent that it is now acceptable to do more or less a lot of various things in the conjugal bed, the real demand for legal paid sex services among married men would probably be less than what it used to be in the past.

Breastfeeding is a similar case. Among higher class women in the past, the practice of hiring wet nurses from lower class women was quite widespread. Part of it was to allow the mother to be free from caring for the baby so that she could enjoy balls and high society, and part of it was the recommendation of the doctors of those days not to nurse in order not to strain the body of the new mother. High class women were considered too fragile for frequent sex or for nursing their young. As a result, prostitutes and/or women from lower classes were for more frequent and intense sex for their husbands and wet nurses from among lower class women were for breastfeeding the young of the nobility.

We now know that both breastfeeding and more frequent and intense sex are not harmful to the health of married women, so that has been an objective change.