We don't know the current peak capability of quantum computing as it is still in its early stages but one thing is sure that it will be a problem for bitcoin because as what is on the paper says about quantum computing, it will be far faster than any computer in the market and in any laboratories. We also have to stop telling people that quantum computing will be able to hack the private key of everyone, yes it has faster calculations but that doesn't mean that it will crack the key in a matter of days, if right now the current brute force duration is the heat death of the universe, maybe with quantum computing, the time it takes will be cut in half but that is still a whole lot of millennia.