Well, criminalizing the victims surely helps /s

Other industries that have had a lot of victims have been made safe with workplace safety standards and unions. Why would that be a worse solution?

Maybe it can be done that way. My interpretation is that the outlawing of prostitution is an old law from long ago when we didn't have the precision for regulation and safety, and it hasn't been revisited yet. Perhaps due to people's personal ethical beliefs.

If each instance of the supposed crime is victimless, where do the supposed victims come from?

Collateral damage?

If an 18 year old girl consents to prostitute herself, she isn't a victim of a "crime of prostitution". But if she was kidnapped as a child from her home country and traffiked to become a prostitute, she is considered a victim of the "industry of prostitution".

None of the crimes against her were prostitution. But the crimes against her were committed in the name of prostitution.