Here’s how I see things:
There are systems within which concepts function.
Mathematics is a system which has a set of concepts in which mathematics functions.
Within the system of mathematics, these concepts are functional.
But there are other systems outside of the system of mathematics.
While the system of mathematics can *also* map to many of these other systems, because it is a self-contained system with its own concepts, it cannot map to everything OUTSIDE of its system, because it is not the same system as the system it is mapping to.
This isn’t taking away from mathematics as a useful system. But it’s pointing out that every system has constraints which ultimately are limitations to that system’s applicability to other systems outside of itself.