Should Nannies be paid differently?

Q) Should Nannies be paid according to their abilities/skill sets?

I wanted to throw out the idea (I cannot commit to an opinion on the subject myself) that a Nanny’s responsibilities can vary and therefore should a Nanny be paid differently according to role? For example:

A Nanny who cares for a newborn-3 year old must oversee every facet of that infant’s care. This is also a vital stage in overall development. The workload can be complex and constant. Should a Nanny who takes care of an infant during this stage be paid more than:

A Nanny who cares for a child in preschool/school and is engaged in food preparation, picking child up from school and taking child on playdates.

Or a Nanny employed to work with older children/teens. Tasks would include: taking teen to classes after school. Staying in the apartment as child/teen does homework or hangs out.
This question does not take into consideration Nannies who have worked through every stage.