It'd quickly turn into a regulated mess. The proper solution is a large-scale extrajurisdictional organization that can take both sides of the trade. Like Uber

It'd quickly turn into a regulated mess. The proper solution is a large-scale extrajurisdictional organization that can take both sides of the trade. Like Uber (without the sexism), it would answer to both the contractors and the customers. Not being a government org would give it the freedom to maneuver. It could exact penalties on abusive clients (fines, banning or worse). It could engage law enforcement on its own terms to combat human trafficking. But also commercially it has many advantages. It would know demand and could thus implement demand based pricing and overall help workers maximize their earnings. A government org is never going to do proper marketing! A company can, and will. And it is a lucrative enough business that it will be able to provide real top quality service to everyone involved without sacrificing safety.