Could Quantum Computers Defeat Bitcoin? Not So Fast. – Decrypt

It would be cost-prohibitive.

And defeating Bitcoin security would simultaneously make it worthless, so there would be no incentive to pay the huge energy and financial cost involved.

Also worth noting: if Bitcoin is hacked, there are bigger issues, because that means American military vehicles, satellites, and missiles have just been hacked as well. As well as the security on almost every website on the internet has also just been made redundant.