Quantum computers can factor numbers faster than traditional numbers, yes, but i don’t think it’s going to be a sudden jump from “impossible” to “now anyone can break any crypto”.

On the other hand, switching crypto algorithms is relatively easy. Breaking crypto is something that’s happened before. There’s already a system in place for TLS for negotiating the best available crypto scheme, and people have already switched away from past, less secure algorithms before.

I think there are so many more problems to solve with building the quantum computers, compared to coming up with or implementing a new crypto scheme.