Robots will do all the restocking of the shelves and cashiers in stores, there will probably be McRobots instead of McDonalds.
Why would we use a very expensive robot to do menial work that a human with minimum wage can do?
No, the ones that should be worried are the ones that their work could not only be replaced but improved by a robot, see lets say some architect which has a huge salary, a robot with his abilities would replace him and save money for the company.
I think that when that happens humans will be the ones doing the menial work, not robots
Chemist who falls in acid will be tripping for weeks.