All you are saying is that you have been been working on trivial software systems and haven't been exposed to anything particularly large scale or complex so far in your career.

Also you must be confusing basic arithmetic (1+1=2) with mathematics in general.

Go read some papers on deep learning architectures or learn about the Fourier Transform then come back and tell us how shallow and simple it is.

Mathematics requires the most sophisticated and deep thinking that the human species is capable of. Very few humans have the raw intellectual capacity required for being a productive mathematician.

> Also all (most) mathematics is not P=?NP level stuff.

The list of open mathematical problems is as varied as it is vast. But even going beyond that, it's clearly evident (e.g. by considering drop-out rates of technical degrees) that most people seem to be having a really hard time even with comparatively elementary mathematics.

> Especially being simplistic (unambiguous, mechanistic) is a feature for what mathematics is used for.

I'll give you "unambiguous" up to a point (there's still enough debate about which axioms are the "correct" ones, though). But "mechanistic" is plainly wrong. The set of true theorems (e.g. of ZFC) is famously undecidable, so there can be no algorithm that can capture all of mathematics.