but it is hard to imagine a modern job that would require one to get fake married ....

Live-in caretaker positions for married housekeeper/butler pairs and other roles are still very much a thing among the super rich! I read an article about it a couple years ago, though heck if I can track it down again now. My conclusion was that while the career had certain temptations (it does pay well, and since a lot of these positions are at vacation properties own by jet-setters who only visit a few weeks a year, you get a lot of privacy from your employer), it also involved way too much emotional labor for jerks for me to ever succeed. Also, I'm not married.