> that's not what people say?

Well, they should, if they want to be honest and mathematically rigorous.

For instance, in the case of NIST's proposed post quantum cryptography standard Kyber that relies on lattice based methods.

> and pre-quantum crypto is also vulnerable to yet discovered classical algorithms?

True, and also disconcerting; with the most reckless being allowing fungible currency reliant on such methods.

We should be working on standardising and moving towards methods that are independent of, rather than rely on, unresolved questions in mathematics.