Being hard to tell apart from something evil doesn't make it the same thing.
And the problem is that the anti-prostitution forces have basically corrupted the word "trafficking" to include any prostitution that involves a woman relocating to do it.
Ya, it's not the same thing but you're still a dick for providing cover for the evil enterprises through making your legal business indistinguishable from their illegal ones so that it's much harder to police the evil ones and therefore the victims of those evil businesses suffer more because of your actions.
It's like if you have a business selling small packs of sugar on the side of the road to passing drivers for them to put into their coffee. There's nothing illegal or immoral about your business, but by doing it you are making it much more difficult for cops to target drug dealers because you are out there looking like you're doing the exact same thing as them so it's harder for them to get drugs off the street and this means that your standing out there doing this is actively harming people almost the same as the real drug dealers are.
If you think that's a stupid example and nobody would actually have a business like that and anyone doing so would actually be a drug dealer and not a sugar merchant then … ya … welcome to the entire point of the analogy.