>My point is not that math never changes -- it should, and does. However, math does not simply rot over time, like code seems to (or at least we simply assume it does). Math does not age out.

Just in the same sense that CS does not age out. Most concepts stick, but I'm pretty sure you didn't go through Στοιχεία (The Elements) in its original version. I'm also pretty confident that most people out there that use many of the notion it holds and helped to spread never threw their eyes over a single copy of it in their native language.

> I'm pretty sure you didn't go through Στοιχεία (The Elements) in its original version

This is like saying "you haven't read the source code of the first version of Linux". The only reason to do that would be for historical interest. There is still something timeless about it, and I absolutely did learn Euclid's postulates which he laid down in those books, all 5 of which are still foundational to most geometry calculations in the world today, and 4 of which are foundational to even non-Euclidean geometry. The Elements is a perfect example of math that has remained relevant and useful for thousands of years.

So that's it. Just because new languages and framework are rising and fading away, it doesn't mean there is nothing kept all along the way. It just that specific implementation is not the thing that people deem the most important to preserve over time.