Also, I'm not saying you need the math to train a model. I'm not sure you even need linear algebra to do that, mostly just programming. That's why I called it the beginning. I was directly responding to your claim that this is all you need __to understand__. Because let's be real, you don't need to know backprop (and thus derivatives and chain rule) to train models. The math is about how to analyze your models. You know, specifically what academia is supposed to be doing. Research and engineering overlap but they aren't necessarily the same thing.
Besides, math education is notorious for being essentially free. Who needs Stanford/Berkeley/MIT when textbooks exist widely. (Btw, CS doesn't typically produce mathematicians)
Linear Algebra is a huge ... space?
And then there's all the other algebras. I'm not sure what you are thinking, like, do you not know matrix multiplication you had better get a clue.