the worker has to keep working at the company because if they quit they have to go home
this means the company can treat them like crap and pay them very little because they can't quit
obviously this isn't entirely correct but if you come across some leftard who is pro H1B abuse try using their shitty language tactics against them and say they must be in favour of indentured servitude
They won't voluntarily self-deport until your country is worse than India...good luck with that.
It doesn't need to be worse than India.
It just needs to be more dangerous. For them.