Won't the same tech also be used by the miners and those who secure the network?
Pretty much stronger and people thought that with the QCs everything is possible. We've got devs as well that goes with the trend and does upgrades in protecting the network to become more secure. And that would be historical if a theft really does a collective effort of taking all of $1M at once but it's unlikely.
I do think that if such a time comes - the community will be ready for it.
I hope so, at least

And will stay with such a thought.