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.