I did a search and it looks like the last time a QC topic was active was more than 3 years ago. That struck me as surprising because I though that QC could pose a threat to the security of BTC keys.
Google has been making exponential progress in the power of their QC machines. I believe I read an article saying that it is possible that within five years QC might be able to crack 128 bit encryption (the stuff bank websites use). I'm not that well versed in the technology of QC. It's just been something I've kept up with in relation to its possible effect on BTC.
Is the consensus here that QC will not be able to crack private keys?
It's not just Google but many individual companies which are onto this project but unfortunately the government is not giving that much freedom to these companies to be able to execute a fool proof plan . Right now the quantum computer which is fully functional is too big to be even carried in by some normal person . You might have to ask for a truck to come.
The security issue with the keys will always be there but what I understand for sure is:
The government sites are more vulnerable as compared to Bitcoins or any other cryptocurrencies and therefore they would prevent any future attack for sure.
If one goes down everything will go down for sure.
Therefore I believe that the quantum computer will come with a lot of restrictions and therefore we don't have to worry much about it ; someway in the future we can also integrate the quantum computing in the Bitcoins and other mining machines this way it would not only be more secure but it would change the whole thing.