Trafficking does still occur. But it is a very small part of the scene.
The difference it has made to workers is huge. Once they were at risk from pimps, clients, and cops. Now if pimps or clients bother them they go to the cops, and the cops protect them. As they should.
As they do for shop keepers, plumbers, and computer programmers.
Make no mistake: Having a law against sex work encourages, and subsidises, trafficking.