I appreciate your point- but isn't it true that any high earning professional is open to the same problem? Money and drugs aren't selective.
True, "High earning professionals" are certainly at risk, but in the main, as a percentage of these workers, less are likely to destroy their lives through their ability to address their own addictive behaviour.
"Trafficking" in the UK relies upon the inability of the wg to properly identify her circumstances and her only remedy, as with almost all people that have failed to stop their addictions, is to deny responsibility and blame someone else for their misfortune. I would hazard a guess that should a punter bump into someone that had actually been trafficked, he would immediately go into the fluffy, knight-in-shining-armour mode and offer the poor girl a safe (In his opinion) home. a home where he thinks he can shag the arse of her for free.
I have no doubt, trafficking exists in some parts of the world, as does slavery continue in many African nations, but here in the UK, not on "our" watch.