> Which is why post-quantum algos were invented.
Yup. And I don't even think quantum resistance was the goal of some of the algos that, yet, happen to be believed to be quantum resistant. Take "Lamport signatures" for example: that's from the late seventies. Did anyone even talk about quantum computers back then? I just checked and the word "quantum" doesn't even appear in Lamport's paper.
> Did anyone even talk about quantum computers back then?
Not unless they have a time machine. Shor's algorithm was discovered in the 90s (sure the concept of a quantum computer predates that, but i don't think anyone really realized they had applications to cryptography)