You'd be surprised:
https://www.reddit.com/r/HappyEndingMassage/comments/13kzcl3/_/jknzko2
Granted, this example is an American-Born Korean but same diff really.
If you read the entire thread you'll realize sex work make a shitton more than a real job, and parlors even more so than private. Private escorts might get one, occasionally two clients a day. Why do you think private girl's schedule are always flexible and available on demand? Cuz they have no clients. AMP (the good ones, anyway) and AAMP's you always have to schedule if you want someone specific.
Actually my understanding most of them specifically goto a school to get trained before flying to the US to do this. Not all of them though. If you actually chat with them it's also pretty evident many of them drive long commutes to the South Bay to avoid friends and family, even co-workers from their day job (some parlor girls only start work at like 4pm), some even have children, and have legal status.