> Slaves don't choose their job, work visa immigrants do.

Some slaves absolutely sell themselves into it, in other to escape poverty, debt, or war[1]. It doesn't change the fact that they do have less rights, less options, and their employer can and will abuse this as evidenced by this thread and a shitload of other HN threads. (and yes, I understand this is unpopular sentiment because the citizens want to believe they are doing a good thing and providing upward mobility and the immigrants don't want to consider themselves slaves)

[1] https://en.wikipedia.org/wiki/Voluntary_slavery

And the early colonisation of north America made use of indentured colonists who where early on preferred to slaves in some cases.

They get taken hostage by seemingly attractive offers. Call it what you want but you're basically a slave to the corporation for the opportunity to get a VISA