Jobs that are ill suited for robots to attend to will be available for poverty-level wages. Many jobs like Accountant, Secretary, Typist, Postal Clerk, and many other office jobs are replaced by computers. Receptionists only exist for sex appeal. Automation replaces most assembly line jobs, except when the cost of labor is less than machine cost. Also, rich people will rediscover old toys as they realize they can't keep up with new toys.
Servants are a sign of status.
They are also a method of relaxing. They will know that a machine could do their job better and cheaper. They also know that it is probably better than the alternative jobs. The master will have a person to look down upon. When you've got cash, servants can disappear if they try to protest.