Cryptography has a peculiar approach to the threat of quantum computers, because it is not acceptable for some of the data and connections encrypted today to become decryptable even thirty, fifty years in the future. That means that the question is not "are QC coming soon" but "might QC plausibly come into existence in the next half century". Since the answer, despite not having a precise consensus, is not "no", here we are.

This is also why you are seeing a lot more progress on PQ key exchanges, as opposed to signatures: signature verification today is not affected by QC fifty years from now, while encryption is.