Thanks... that seems really labor intensive.
It's done with slave labor.
It's called pig butchering. You kidnap people, hold them in Cambodia or whatever (lots of locations where local criminal gangs rule) so the locals don't bother checking for literally kidnapped slaves.
If police stop by, pay them off and make up a story about debts and punishment.
Then you use the slaves to scam others in pig butchering scams. If the slaves refuse, you beat them until they comply.
https://www.propublica.org/article/pig-butchering-scams-raid...
But with big payoffs.
Labor is dirt cheap in some parts of the world, especially compared to the tens of thousands of dollars American retirees might have access to!