I think your last paragraph relies on the concept that all sex workers are always victims and no one else (the buyers, coworkers etc) is ever a victim.
That really can't be true in practice. So we need a more nuanced approach.
People argue about these specific numbers because frankly it's a hard population to get honest surveys of, but here's one I found.
https://pubmed.ncbi.nlm.nih.gov/9698636/
>As adults in prostitution, 82% had been physically assaulted; 83% had been threatened with a weapon; 68% had been raped while working as prostitutes;
...
>Eighty-eight percent of these respondents stated that they wanted to leave prostitution, and described what they needed in order to escape.
If those numbers are even close to reality I think it's hard to argue that the negatives of prostitution don't far outweigh any positives.
That said I think it's not at all obvious what the solution is here because clearly criminalizing prostitution is ineffective at eliminating prostitution.
I wasn't able to find any stats on violence in a country where it is both legal and normalized, but I did find this paper by a doctor of psychology about the trafficking and abuses that still occur under the German system.
https://digitalcommons.uri.edu/dignity/vol3/iss3/5/
I'm open to evidence to the contrary, but it seems like in many ways the legalization and normalization of prostitution has both failed to protect sex workers from violence and has normalized the trafficking and pimping of these women.
Sadly, people with mental health issues and difficult families being preyed upon by abusers is common, even here in the US.