I think we are still years away from computers that will crack blockchains. As the industry evolves, will will start seeing modifications made so that bitcoin and other protocols are quantum-proof.
Agree. I believe that before Quantum Computers would become practical in the mainstream world, the blockchain would've evolved at some point to mitigate attacks from such machines. One thing for sure is that Bitcoin is not only the strongest cryptocurrency in existence today, but it is also the most active cryptocurrency in development. Therefore, devs working hard within Bitcoin, will find out a way to implement Quantum-resistance within the cryptocurrency to avoid disruption from Quantum computers in the future.
If there's enough consensus from the Bitcoin community to achieve such upgrade in the future, then there should be nothing to worry about. I'm sure that everyone will agree to implement such improvement to help protect the Bitcoin ledger for many years to come. Just my opinion
