I am absolutely not saying that human trafficking doesn't exist. Where are you getting that from? Of course trafficking exists!
Nevertheless, the majority of women who are sex workers voluntarily choose their profession. They are not coerced. This is a choice they freely make as independent adults. To assume otherwise is not only patronizing, but it's the driving force of most laws worldwide that make it so much more difficult for sex workers to work in their chosen occupation.
Lots of sex workers have their own cars, by the way.