I might misinterpret the parent, but I think the parents idea is more that it helps when deriving the math used in a lot of video game programming. (e.g. simplifying expressions in shader code, or deriving closed forms for intersection tests).

Where this might help is if you don't have a strong background in algrabra, and don't know all the properties of e.g. quaternions by heart. You'd implement essentially the answer that you get after playing with a computer algebra system

Yes, exactly! A CAS lends you the skills of a mathematician once you already have the knowledge of a mathematician.

Computer Algebra Systems basically help you do math. If you want to integrate an expression, or solve a system symbolically, you can, of course, sit down and do that with pen and paper. Or you can "ask" a CAS to do this for you.

This is much easier than it sounds. And it's fun too: https://wordsandbuttons.online/sympy_makes_math_fun_again.ht...

I suppose, a lot of not games but game developers use CASes and we don't even know :-)