Victorian reformers had rescue missions for prostitutes who wanted to leave. Increased economic opportunity gave poor girls other options. Law enforcement made it more difficult for entrapment to occur. Prostitution wasn't eliminated but at least it was voluntary.
The British open borders policy has brought back an evil - involuntary prostitution, sex slavery - that was mostly wiped out a century ago in that nation.
Mrs VS
I do not disagree. I was merely attempting to point out that such evils are nothing new.