Qatar did a lot to ensure Temporary Worker Immigrants visas weren't tied to a specific employer (which led to abuses like if you don't do this you're fired and you'll be shipped out of the country)
 
Where is the line between bargains and exploitation?

Do they have safety? Food? Shelter?

What is the direction of the progress? How much further is there to go? Who will care about this specific question in 2 or 3 years?

The Truth of the Matter: World Cup Geopolitics - YouTube