If quantum computing would progress just like in the last 30 years it may take 300 years before it can be useful.
As has been previously pointed out, the 2001 and 2012 quantum factorisation records may be easily matched with a dog trained to bark three times [33]. We verified this by taking a recently-calibrated reference dog, Scribble, depicted in Figure 6, and having him bark three times, thus simultaneously factorising both 15 and 21. This process wasn’t as simple as it first appeared because Scribble is very well behaved and almost never barks. Having him perform the quantum factorisation required having his owner play with him with a ball in order to encourage him to bark. It was a special performance just for this publication, because he understands the importance of evidence-based science.
I loved this quote as well
It is one of those domains where success would land you in a gilded prison.
Consider the likelihood of managing that without alerting the authorities to what is going on.