"Usefulness" and "utility" both mean nearly the same thing. Usefulness: the quality or fact of being useful. To me, the word "usefulness" sounds rather awkward and could raise doubt among some people as to if it's even a word (although it is).

What is the word usefulness mean?

: the quality of having utility and especially practical worth or applicability.

What is the meaning of usefulness in economics?

Usefulness: Is is used to describe if a resource is practical and cost effective in nature and if it can be used in productive activity.