The reason it's possible for people to exploit other people in the sex industry is because the industry is criminalized. It has the same violent dynamics as many other types of violence, but it goes even further because the industry is criminalized.
I often give the example of a nurse who works in a hospital. She may be under the control of someone abusive who might take her entire paycheck, who beats her, who forces her to work overtime. Fairly quickly, she may turn to her co‑workers and ask for help because she is in a difficult situation. This situation will usually stop. She will go to the police and she will be taken seriously.
When you're in a criminalized industry, where everyone has to protect themselves from the police, where the driver, the receptionist, the client can all go to jail, it gives abusers the opportunity to be violent or take advantage of people. That's why it's impossible to separate human trafficking concerns from the decriminalization of sex work. Once decriminalization occurs, then there are levers to stop these types of exploitation.