Yes, a quantum computer can hack bitcoin. In fact, any computer can hack bitcoin if given enough time and resources.
The reason why quantum computers are particularly well-suited for this task is because they can perform large number of calculations very quickly. This means that they can try out many different hacks in a short period of time and are more likely to find a successful one.
While it is possible for a quantum computer to hack bitcoin, it is not yet clear how practical this would be. Such a computer would need to be extremely powerful to be able to carry out the necessary calculations in a reasonable amount of time.
At the moment, there are only a handful of quantum computers in the world and they are all still in the early stages of development. It may be some time before a quantum computer powerful enough to hack bitcoin becomes available.
Even if a quantum computer could be used to hack bitcoin, it is not clear that this would be desirable. Once a successful hack was carried out, the value of bitcoin would plummet as people lost faith in its security.
This could ruin the bitcoin economy and lead to financial chaos. It is therefore in everyone’s best interests to ensure that quantum computers are not used for such purposes.