Fortunately it's never been needed. Every time it's come up the problem has been solvable with high school algebra level math skills (you need to know what the lcm is and that's covered in middle school in many places). If you knew the CRT you could jump straight to a solution, but a solution was easily derived using algebra and a couple loops.

I think a lot of people are so focused on "optimal" solutions they fail out or burn out quickly, ignoring the ugly "just loop a bunch of things" option.

I'm by far an expert on AoC, but the number of people I see every year on day 2 or 3 saying "IT'S TOO MUCH" because they were trying to implement some crazy algorithm when basic array operations and for loops would solve it...

I flunked out of high school. I don't even properly understand algebra, never mind any sort of complex math. I have no CS degree. I've completed most of it in some gross PHP that completed before next year on a single core in an old laptop.

If "knowledge of obscure algorithms" is a requirement either I'm a once in a generation genius or... it's not a requirement.