Traditionally, and still, women and girls are tacitly understood to be not quite human, and of no importance. Therefore, 'slavery' was what happened to men.
So, of course, is 'torture': Some Canadian nurses tried to point out that using the term only in the context of soldiers in wartime was missing the point:
In wartime, civilian women and children are usually the greatest number who are physically attacked and deliberately harmed by some of the enemies.
True. But then, the same goes in peace-time, and in every country. The threat to women and children are some of the men, everywhere.
Because this is Mumsnet, it may not be obvious that not only women, but other groups, too, are tacitly understood to be not quite human, and of no importance:
Age, and disability, can and will put humans at risk of being transported "within a country, for the purposes of that person being exploited".
Relatives, 'care' organisations, 'homes', and 'romance fraudsters' will extract the maximum money, frequently requiring a change of abode to facilitate it.
Predators will of course also use any opportunity to take advantage of prey:
Repeatedly, rapists and sadists are discovered to be exploiting the incarceration of disabled and/or old people to rape and assault them. e.g. the recent case of a man who had imprisoned his eighty year old mother, for the purpose of daily rape.