Because in a significant portion of cases, they are. They’re owned by someone and didn’t choose to sell themselves.

The fact that trafficking is such a meaningful portion of sex work is a big part of the reason it hasn’t been legalized most places. I think it should be legalized and regulated to try to make it harder to have the workers be people who don’t freely and fully consent, but the increase in demand if it’s legal could make it worse in the short term at least.