I worked in Chrome for a while, but for past few years I worked in security related areas, both at Google and at Facebook. You could make the case that the mathematics I’ve learned helped me understand how RSA and ECC work, but that has actually been mostly irrelevant in my experience, unlike things like system design, vulnerability detection and management, fuzzing, reverse engineering, which I have mostly learned on the job, not at university.

If people are finding that they aren't using what they learned at university in their career, it's the career that's the problem, not the university education.

This is a bit myopic with respect to how normal people view university education. For a typical person, the point of education is not to learn things, but to obtain a degree. The point of degree is to get a good job. If they manage to get a good job, that’s a success, and nothing more is expected from the university education: people learn how to do the job mostly on the job anyway. In this context, if people don’t use what they learned in the university in the careers, that’s okay, what matters for normal people is the career, not the learning. Of course, it might be different for you (it is different for me, I love learning for learning’s sake), but that’s observably not how most people approach life.