Maybe that's why sex traffickers are reported so often in the Netherlands. The girl will tell a client or coworker, who'll tell the police. Or they'll go directly to the police, if they can.

Where it's illegal, no-one talks to the police.

Probably because they have a strong safety net and there's not enough Dutch men and women willing to engage in sex work to meet demand.

I would also imagine the demand is much higher since it is illegal in surrounding areas and most of the world. If that weren't they case I'm guessing demand would be much lower. It's a problem that can't be solved in isolation.

The main question is - why coerced prostitutes are not going to law enforcement? What prevents them? Will they be deported for that?

This problem probably can be solved with technology - make Airbnb for amateur sex workers :)