[i_think_so]

Am I missing something fundamental here?

If Algo-A and Algo-B both rely on "factoring big numbers is hard!" then once the Quantumpocalypse occurs, breaking Algo-B(Algo-A(plaintext)) is no harder than asking ChatGPT 99.5 to add an extra step in your vibe coded cracking engine's frontend, such that it now does B_breaker < cyphertext | A_breaker >> plaintext.lol or whatever the equivalent is for the fashionable language of the that future day.

[voxic11]

He was saying hybrid encryption as in use both a well established classical "factoring big numbers is hard!" algo and also a fancy new post quantum cryptography algo. That way if it turns out the fancy new algo can be broken by non-quantum computers at least you aren't in a worse position than you were in before because you are still protected by the well established classical algo.

[tardedmeme]

You have to break both algorithms. One of them is quantum-safe if it's secure, but it could also be completely insecure like supersingular isogeny was.