Your friends are probably not the best source on the matter. Go on YouTube and listen to interviews with actual sex workers in places where it is institutionalized (e.g. Amsterdam, New Zealand). There are plenty of Vice documentaries e.g. https://youtu.be/Q8_UGthO3CM
I’d reiterate that my sources are trained professionals who already work with the most vulnerable people who society has already failed — those who sleep rough and who have turned to or are thinking of turning to sex work. I accept your point though, that “sex worker” is a wide bracket that encompasses a range of personal situations though. Thanks for the link.