Oh pull your head in.
I gave real examples. I was a manager of 10 people on 457s. They were French, Italian, Thai and Indian. I worked with an an additional 10 457s from UK and US.
In my example yes sometimes they are willing to be paid less than local labour, is it an abusive subsistance pay? no. Is it a fair amount for the role? yes. I required degree qualified engineers and geologists for a project and it was impossible to compete against the FIFO pays, no one local would apply for it because it was not a permanent role and wasn't as high paying as a FIFO role. There was also very few experienced staff available in Australia due to the nature of the roles.
There was no stealing of local jobs. I work in an international industry where people move country to country all the time following the work.