And by the way, there are plenty of British actors who play U.S. Americans on TV and movies, but it rarely happens the other way.
For example, House, Several actors on Prodigal Son, Billions, several on Homeland, several on Walking Dead, Yellowstone, and many others. Even Idris Elba and Kate Winslet have played someone from the U.S.
Gwyneth Paltrow played a Brit in two movies, and Renee Zellweger in one movie.
I don’t think you understand what an H1-B visa is, if you think Anderson was one.
She was discovered on a jumbotron at a sporting event. She was beautiful. A Canadian company hired her as a model, then Playboy featured her, and things took off from there.
I’m sure she didn’t take a job away from any other beautiful American girl with nice boobs.