I think you're saying a pithy saying proves nothing (Voltaire), which is true; sometimes it summarises a line of argument though.

Math is a mental map which coincides with reality in useful ways. Different maps can also be useful. The models we construct are based on arbitrary axioms which we hold to be true. Different axioms could lead to different theories which are just as useful. So it isn't discovered (i.e. mapping directly to reality and waiting to be discovered), it is created.

To pick one example, adding the concept of zero changed our model/map of reality fundamentally without changing reality.

You have a minority view on this argument, though. Scientific and structural realism both reject the idea that math is just a map. You've got company with the instrumentalists and antirealists, but the majority consensus is that math is somewhere between the structure underlying the territory to all the territory.

Zero was already part of the territory. Lack of something is a very normal state in the universe. Once we added it to our understanding of math, we were discovering it, not creating it. Of course people who are scientific or structural realists would agree it didn't change reality - because reality already had it, whether we knew it or not.