Do you honestly believe that developers from various blockchains will sit idly by and allow a blockchain project they are passionate about without planning for attacks by quantum computing?
Developers behind Ethereum and Cardano are aware of this issue and are beginning to work on approaches to make its blockchain quantum resistant. I acknolwedge such a solution will be very complex, but I doubt QC will crack the public and private-key cryptography before a migration to a quauntum-resistant chain.
QC affecting crypto is only the tip of the iceberg. How about the legacy financial system and how this will be impacted? If anything, this is more of a compelling issue in terms of people affected and $ amounts involved.
https://www2.deloitte.com/nl/nl/pages/risk/articles/quantum-risk-to-the-ethereum-blockchain.html
