Why demanding celibacy and chastity of priests no longer appears practical

I want to come back to this fascinating question of why demanding celibacy and chastity of priests no longer appears practical. Or, in other words, why until not that long ago did European Christian societies assume that lots of people were never going to marry? My guess is that until fairly recently, lots of people tended to be too hungry, tired, cold, and ill to feel particularly strong sexual urges. Sure, the healthiest always tended to be plenty lusty, but perhaps a sizable fraction didn't.