I think enforcement is the missing piece here. The police are not enforcing. The Crowns are not pressing charges.
The question is, the act does not cause harm to exploited people.... Where there is harm to women, it's because of the lack of enforcement. The refusal of the police to enforce the law leaves women at the mercy of the pimps and the sex buyers, who get to be as controlling and as violent as they want.
It really does harm women to know that they are deemed not worthy of protection even when the law of the country says that what is happening to them is wrong. It harms all of the women in the community when we see that other women are being sold, denigrated and hurt and nothing happens to the man or the men who caused that harm.
Before the law, women didn't go to the police, and they don't go now because the police have not changed their attitudes or their behaviour about the sex buyers. Before the act, the police arrested women almost exclusively, and after the act, in B.C., in Vancouver especially, the police stopped arresting anybody. They have effectively disappeared prostitution, because they have no numbers, no arrests, no cases.