MGP MUL

Jest and Robot Framework are both named 'Testing Framework' on many sites that I visit. Both aim at testing the client-side of a web application.

I am aware there are differences in their implementation (JavaScript vs Python) and their purpose (Unit test vs Acceptance test). Still, they seem to overlap a lot. Is there a use case to implement BOTH testing frameworks? Suppose a team has written lots of Jest test cases, and code coverage is really good. Is there still a reason to add Robot Framework on top of that?