As usual the markets aren't listening to the answer he gave "Useful". He needs to qualify that - certainly not mainstream for consumers, probably not for most programers but for focussed markets and applications. the time is now, and it is eating into some of the "AI" ideas. Is trawling through data of chemical/drug tests an AI application (it is far faster than traditional) or a Quantum one where you can do orders of magnitude more than Blackwall powered AI in less time.
Will be interesting to hear the discussions onThursday at CES when the Quantum industry has their say
The quantum stocks have run up too fast. There are over 300 companies working on AI and quantum with most of them being private. This only leaves a few public traded companies. The market will adjust over time.