If you’re supporting windows anyway you should use their tooling. This isn’t controversial, MSVC is a good compiler supported by good developers. I find MSVC more reliable than MinGW on windows as well. I recommend maintaining a single CMake project so that you can switch between compilers and build tools.
I majored in math and have so far a great career in software. I don’t think knowing math separates me out from CS grads generally. However, math majors largely chose to major in Math because we like problem solving. Plenty of CS grads major in CS because they are expected to. Being a passionate problem solver gets you pretty far.