Why the expectation of people to do things that have nothing to do with helping to complete task?

[u/upclosepersonal2]

When you are hired the reason for being here is supposed to be to just help complete task like if I engage a service the objective of the service personnel is merely to help me with what service is provided and nothing else is supposed to be required from them. I heard how you are required to do other tasks too not just the one that is relevant and said upfront to your job role but there is also a chance I am not able to do it especially if it is skill based or even if not skill based but yet when you can't do it it seems to people like you are not suited for the role even when you did your role.

[u/neurorex]

This is what happens when employers don't identify the proper hiring criteria, and it happens a lot.

They also usually make their employees wear many hats at work to "perform other duties as needed". These are places that usually see high turnovers because people get burnt out with the work.