Now you are confusing maths with Physics! Physics is about describing the fundamental behaviour of reality, and so it is rather natural to think of the work as

Now you are confusing maths with Physics! Physics is about describing the fundamental behaviour of reality, and so it is rather natural to think of the work as a process of discovering how to best describe it. What maths is, is harder to say. Certainly it starts by just picking a set of rules, thus inventing a new thing with some properties. But, much like how a developer might ”invent” a program that solves some problem, but only ”discover” the bugs they wrote, so the mathematician too must spend a lot of time working with their newly created object to ”discover” what it really does.